(8 July 2016)

General Atomic and Molecular Electronic Structure System

                GAMESS User's Guide
              Department of Chemistry
               Iowa State University
                   Ames, IA 50011

literature citations:

     "General Atomic and Molecular Electronic Structure System"
     M.W.Schmidt, K.K.Baldridge, J.A.Boatz, S.T.Elbert,
     M.S.Gordon, J.H.Jensen, S.Koseki, N.Matsunaga,
     K.A.Nguyen, S.J.Su, T.L.Windus, M.Dupuis, J.A.Montgomery
     J.Comput.Chem. 14, 1347-1363(1993)

     "Advances in electronic structure theory: GAMESS a decade later"
     M.S.Gordon, M.W.Schmidt    Chapter 41, pp 1167-1189, in
"Theory and Applications of Computational Chemistry, the first forty years"
      C.E.Dykstra, G.Frenking, K.S.Kim, G.E.Scuseria, editors
       Elsevier, Amsterdam, 2005.

More on GAMESS will be found in the following site:

Contents of this manual:

Section 1 - INTRO.DOC - Overview (This page) Section 2 - INPUT.DOC - Input Description Section 3 - TESTS.DOC - Input Examples Section 4 - REFS.DOC - Further Information Section 5 - PROG.DOC - Programmer's Reference Section 6 - IRON.DOC - Hardware Specifics

Contents of Section 1:

Graphical display of results is possible using MacMolPlt, a 
back end visualizer of results contained in GAMESS' output 
files.  MacMolPlt can be downloaded freely from here.

Input files can be prepared using MacMolPlt, or using a 
program named Avogadro, which is a molecule builder: Avogadro

GAMESS itself, and both graphics programs, run on all 
common desktop platforms: MAC OS X, Linux, or Windows.  
There is a simple batch queue program named GamessQ to 
schedule GAMESS runs on a desktop: GamessQ

Of course, GAMESS is most often run on a dedicated computer 
facility instead of your desktop, but all users can benefit 
from installing the two graphics programs on their desktop.

Movies showing how to use GAMESS and GamessQ on desktop 
platforms, and other information about what GAMESS can do 
are at Jan Jensen's blog.


    A wide range of quantum chemical computations are 
possible using GAMESS, which

   1. Calculates RHF, UHF, ROHF, GVB, or MCSCF self-
      consistent field molecular wavefunctions.

   2. Calculates the electron correlation energy correction
      for these SCF wavefunctions using
        a) Density Functional Theory (DFT),
        b) Valence Bond Theory (VB)
        c) Configuration Interaction (CI), 
        c) Many Body Perturbation Theory (MP2),
        e) coupled-cluster (CC) or Equation of Motion CC
           (EOM-CC) methodologies.
        f) for MCSCF, generates R12 basis set corrections
           by an interface to the MPQC package.
      See the summary table below for valid combinations.

   3. Calculates semi-empirical MNDO, AM1, or PM3 models
      using RHF, UHF, ROHF, or GVB wavefunctions.

   4. Calculates analytic energy gradients for any of the
      SCF wavefunctions, DFT or TD-DFT, closed or open
      shell MP2, or closed shell reference CI.

   5. Optimizes molecular geometries using the energy
      gradient, using internal or Cartesian coordinates.

   6. Searches for saddle points (transition states) on the
      potential energy surface.

   7. Computes the energy hessian, and thus normal modes,
      vibrational frequencies, and IR intensities.  Raman
      activities are a follow-up option.

   8. Obtains anharmonic vibrational frequencies and
      intensities (fundamentals or overtones).

   9. Traces the intrinsic reaction path from the saddle
      point towards products, or back to reactants.

  10. Traces gradient extremal curves, which may lead from
      one stationary point such as a minimum to another,
      which might be a saddle point.

  11. Follows the dynamic reaction coordinate, a classical
      mechanics trajectory on the potential energy surface.
      This is also known as "direct dynamics".

  12. Computes excited state energies, wavefunctions, and
      transition dipole moments at various levels:
         a. SCF (e.g. ROHF or MCSCF)
         b. CIS (RHF plus single excitations)
         c. much more general CI functions
         d. time dependent DFT (or TDHF)
         e. Equation of Motion-Coupled Cluster
      with gradients for SCF, CIS, TD-DFT and GUGA CI.

  13. Searches for the minimum energy crossing point
      between two intersecting potential energy surfaces,
      which have different spin or space symmetry.

  14. Finds conical intersections between surfaces of the
      same spin and space symmetry, at CIS, TDDFT, or MCSCF
      levels.  MCSCF-level non-adiabatic coupling matrix
      elements (NACME) between these states may be found.

  15. Evaluates relativistic effects, including
         a. scalar corrections, via the local unitary
            transformation version of infinite order two
            component theory.  Gradients are available.
         b. spin-orbit coupling matrix elements and the
            resulting spin-mixed wavefunctions.

  16. Evaluates the static linear polarizability and the
      first and second order hyperpolarizabilities for all
      wavefunctions, by applying finite electric fields.

  17. Evaluates both the static and frequency dependent
      polarizabilities for various non-linear optical
      processes, by analytic means, for RHF wavefunctions.
      Nuclear derivatives of the polarizabilities lead to
      analytic Raman and hyperRaman spectra, also for RHF.
      Imaginary frequency dependent polarizabilities can
      also be obtained, again for RHF only.

  18. Obtains localized orbitals by the Foster-Boys,
      Edmiston-Ruedenberg, or Pipek-Mezey methods, with
      optional SCF or MP2 energy analysis of the LMOs.

  19. Calculates the following molecular properties:
         a. dipole, quadrupole, and octupole moments
         b. electrostatic potential
         c. electric field and electric field gradients
         d. electron density and spin density
         e. Mulliken and Lowdin population analysis
         f. virial theorem and energy components
         g. Stone's distributed multipole analysis

  20. Models solvent effects by discrete particles
         a. effective fragment potentials (EFP)
      or by various continuum models
         b. polarizable continuum model (PCM)
         c. solvation model density (SMD),
            a reparameterization of PCM
         d. surface and simulation of volume polarization
            for electrostatics (SS(V)PE)
         e. conductor-like screening model (COSMO)
         f. self-consistent reaction field (SCRF)
      It is possible to make a layer model consisting of QM
      atoms, surrounded by EFP particles, embedded in PCM.

  21. Performs all-electron calculations based on the
      Fragment Molecular Orbital (FMO) method.

  22. Models the formation of aperiodic polymers with the
      Elongation Method.

  23. Perform QM/MM style HF, DFT, GVB, MCSCF, MP2 and
      TDDFT calculations, using the integrated QuanPol

  24. When combined with the plug-in TINKER molecular
      mechanics program, performs Surface IMOMM (SIMOMM)
      or IMOMM QM/MM type simulations.  Download from

  25. When combined with the plug-in NEO program (Nuclear
      Electron Orbitals), performs quantum mechanics
      computations of nuclear structure.  NEO's code is
      included with GAMESS source distributions, see
      the directory ~/gamess/qmnuc.

  26. When combined with the plug-in XMVB program,
      performs valence bond calculations.  Please contact
      Professor Wei Wu of Xiamen University for more
      information: http://ctc.xmu.edu.cn/xmvb/index.html.

  27. When combined with the plug-in NBO program, performs
      Natural Bond Orbital analyses.  This program is
      available at http://www.chem.wisc.edu/~nbo6, for a
      modest license fee.

  28. Interfaces to the Atoms in Molecules Package, for
      the Quantum Theory of Atoms in Molecules analysis.
      See http://aim.tkgristmill.com/index.html 

Many of these calculations may be performed in parallel!

    A quick summary of the current program capabilities
is given below:
               SCFTYP= RHF    ROHF   UHF    GVB    MCSCF
                       ---    ----   ---    ---    -----
SCF energy             CDFpEP CDFpEP CDFpEP CD-pEP CDFpEP
SCF analytic gradient  CDFpEP CDFpEP CDFpEP CD-pEP CDFpEP
SCF analytic Hessian   CDFp-- CDFp-- CDFp-- CD-p-- -D-p-

VB energy              C----- C-----

MP2 energy             CDFpEP CDFpEP CDFpEP ------ CD-pEP
MP2 gradient           CDFpEP -D-pEP CD-pEP ------ ------

CI energy              CDFp-- CD-p-- ------ CD-p-- CD-p--
CI gradient            CD---- ------ ------ ------ ------

CC energy              CDFpE- CDF-E- ------ ------ ------
EOMCC excitations      CD--E- CD--E- ------ ------ ------

    semi-empirical models:

DFT energy             CDFpEP CD-pEP CDFpEP  n/a    n/a
DFT gradient           CDFpEP CD-pEP CDFpEP  n/a    n/a
DFT Hessian            CDFp-- CD-p-- CDFp--  n/a    n/a
DFTB energy            yes/FP ------  yes    n/a    n/a
DFTB gradient          yes/FP ------  yes    n/a    n/a
DFTB Hessian           yes/F  ------  yes    n/a    n/a

TD-DFT energy          CDFpEP ------ CDFp--  n/a    n/a
TD-DFT gradient        CDFpEP ------ ------  n/a    n/a
TD-DFTB energy         yes/P  ------ ------  n/a    n/a
TD-DFTB gradient       yes/P  ------ ------  n/a    n/a

MOPAC energy           yes    yes     yes    yes    n/a
MOPAC gradient         yes    yes     yes    no     n/a

  C= conventional storage of AO integrals on disk
  D= direct evaluation of AO integrals whenever needed
  F= Fragment Molecular Orbital methodology is enabled.
     "F" pertains to the gas phase; for FMO with PCM or EFP
      there are further restrictions not specified here.
  p= parallel execution
  E= Effective Fragment Potential discrete solvation
  P= Polarizable Continuum Model continuum solvation
         "yes" for MOPAC means "no" for FMO.

Numerical gradients and fully or partly numerical Hessians
are available for any energy or gradient in this table.

History of GAMESS

    GAMESS was put together from several existing quantum 
chemistry programs, particularly HONDO, by the staff of the 
National Resources for Computations in Chemistry.  The NRCC 
project (1 Oct 77 to 30 Sep 81) was funded by NSF and DOE, 
and was limited to the field of chemistry.  The NRCC staff 
added new capabilities to GAMESS as well.  Besides 
providing public access to the code on the CDC 7600 at the 
site of the NRCC (the Lawrence Berkeley Laboratory), the 
NRCC made copies of the program source code (for a VAX) 
available to users at other sites.  The original citation 
for this program was
       M. Dupuis, D. Spangler, and J. J. Wendoloski
     National Resource for Computations in Chemistry
       Software Catalog, University of California:
           Berkeley, CA (1980), Program QG01

    This manual is a completely rewritten version of the 
original documentation for GAMESS.  Any errors found in 
this documentation, or the program itself, should not be 
attributed to the original NRCC authors.

    The present version of the program has undergone many 
changes since the NRCC days.  This occurred at North Dakota 
State University from 1982 up to 1992, and now continues at 
Iowa State University to the present.

    It would be difficult to overestimate the contributions 
Michel Dupuis has made to this program, in its original 
form, and since.  This includes the donation of code from 
HONDO, and numerous suggestions for other improvements.

    The continued development of this program from 1982 on 
can be directly attributed to the nurturing environment 
provided by Professor Mark Gordon, at North Dakota State 
and then Iowa State University.

    It is important to also single out Professor Emeritus 
Klaus Ruedenberg of Iowa State University, whose group is 
responsible for the determinant technology lying underneath 
the MCSCF programs in GAMESS.

    Even when our students and postdocs leave Iowa State, 
many continue to make contributions to GAMESS.  In 
addition, we have also included many codes developed in 
other groups over the years, so that the list of authors of 
GAMESS is actually much longer than the author list of the 
1993 J. Comput. Chem. article.  A complete list of authors 
may be found at the top of every log file from a GAMESS 

     Funding of many of the developments in GAMESS from 
1982 to the present time was, and is provided by the Air 
Force Office of Scientific Research.  This has always been 
the backbone of the support for GAMESS.

    In late 1987, NDSU and IBM reached a Joint Study 
Agreement.  One goal of this JSA was the development of a 
version of GAMESS that was vectorized for the IBM 3090's 
Vector Facility, which was accomplished by the fall of 
1988.  This phase of the JSA led to a program which is also 
considerably faster in scalar mode as well.  The second 
phase of the JSA, which ended in 1990, was to enhance 
GAMESS' scientific capabilities.  These additions include 
analytic hessians, ECPs, MP2, spin-orbit coupling and 
radiative transitions, and so on.   Everyone who uses the 
current version of GAMESS owes thanks to IBM in general, 
and Michel Dupuis of IBM Kingston in particular, for their 
sponsorship of GAMESS during this JSA.

    During the first six months of 1990, Digital awarded a 
Innovator's Program grant to NDSU.  The purpose of this 
grant was to ensure GAMESS would run on the DECstation, and 
to develop graphical display programs.  As a result, the 
companion programs MOLPLT, PLTORB, DENDIF, and MEPMAP were 
modernized for the X-windows environment, and interfaced to 
GAMESS.  These programs now run under the X-windows 
environments, and many other X-windows environments as 
well.  The ability to visualize the molecular structures, 
orbitals, and electrostatic potentials is a significant 
improvement.  These graphics programs eventually formed the 
nucleus of the program MacMolPlt.

    Parallelization of GAMESS began in 1991, with most of 
the early work and design strategy done by Theresa Windus.  
This benefited greatly from the ARPA sponsorship of the 
Touchstone Delta experimental computer.  Message passing 
used the TCGMSG library of Robert Harrison in the early 
years, up to 1999.  Parallelization of GAMESS has turned 
into a multi-year process as detailed below.

    The DoD awarded a CHSSI grant to ISU in 1996 to extend 
that scalability of existing parallel methods, and more 
importantly develop new techniques.  This brought Graham 
Fletcher on board as a postdoc, and led to the introduction 
of the Distributed Data Interface (DDI) programming model.  
The first version of DDI, written at ISU, was used from 
June 1999 to May 2004.  Ryan Olson, with help from Alistair 
Rendell of Australian National University, rewrote DDI 
entirely in C, adding optimizations for the commonplace SMP 
nodes, especially System V memory use.  Dmitri Fedorov of 
the National Institute for Advanced Industrial Science and 
Technology added the concept of subgroups at the same time.  
This combined new version of DDI has been the message 
passing support layer for GAMESS since May 2004.

    The DoE awarded a SciDAC grant to ISU in 2002 to enable 
additional scientific capabilities in GAMESS, with emphasis 
on scalable algorithms.  To date, this has supported 
parallelization of the EFP solvent molecule, and new codes 
for analytic MCSCF Hessians, and open shell MP2 gradients.

    Some summary of these various grants and initiatives is 
in order.  The 1982 version of GAMESS contained roughly 
80,000 lines of FORTRAN code, implementing the present five 
wavefunction types, and analytic nuclear gradients for 
each, enabling geometry optimization and transition state 
search, and numerically differentiated frequencies.  The 
only electron correlation method available was GUGA based 
CI computation.  All computations were in the gas phase.

    By 2005, GAMESS had grown to roughly 650,000 lines of 
FORTRAN.  Analytic hessian computation is now routine at 
the SCF levels.  Electron correlation is now treated with 
direct determinant CI codes, and in addition perturbation 
theory, density functional, or coupled cluster methods 
(with analytic gradients for some of these) may be used.  
New AO integral codes, including effective core potentials 
are used, and direct AO integral computation is possible.  
Discrete and continuum models for solvated molecules are 
provided, and there is an associated program for surface 
chemistry.  Additional chemistry runs are provided, such as 
reaction paths and dynamical trajectories, IR and Raman 
spectra, anharmonic vibrational corrections, static or 
frequency dependent polarizabilities, transition moments, 
and spin-orbit couplings.  Scalar relativistic corrections 
can be applied to any computation.  Improvements or 
complete rewrites have been made for geometry searches, SCF 
convergers, internal coordinates, ease of use, available 
basis sets, and so on.  The majority of these computations 
can be run on parallel computers.

    The rest of this section gives more specific credit to 
the sources of various parts of the program.  The order 
here is partly chronological, and partly logical.  If you 
are one of the programmers, and discover your contributions 
have not been detailed properly, please let us know.

                       * * * *

    GAMESS is a synthesis, with many major modifications, 
of several programs.  A large part of the program originate 
from HONDO 5.  

    For sp basis functions, modified Gaussian76 s,p,L shell 
code is used.  Both the sp rotated axis integrals and the 
sp gradient packages were modified in 2001 by Jose Maria 
Sierra of Synstar Computer Services in Madrid, Spain.  The 
sp integral routines were modified in 2003 and in 2004 by 
Kazuya Ishimura of the Institute for Molecular Science to 
use McMurchie-Davidson quadratures for the basic axes-1 
integrals, after which they are rotated ala Hehre/Pople.  
For spd functions, the s,p,d,L shell rotated axis code 
written by Kazuya Ishimura of the Institute for Molecular 
Science is used.  For integral quartets with higher angular 
momentum, the s,p,d,f,g Electron Repulsion Integral 
Calculator (ERIC) code written by Graham Fletcher at 
NASA/Eloret in 2004 is used, provided the total angular 
momentum of the quartet is no more than 5.  Both rotated 
axis codes, the sp gradient code, and ERIC share a common, 
fully accurate evaluation of Fm(t) integrals, and have been 
tested for very small (down to 0.005) and very large 
(1.0d+11) Gaussian exponents.  The Rys polynomial program 
of Michel Dupuis is used to handle the general integral 
case: s,p,d,f,g, or L shells.  HONDO 1e- and 2e- Rys 
routines were redimensioned to handle up to g shells by 
Theresa Windus at North Dakota State University in 1991.  
AO integrals by Rys quadrature for energy and property 
values were extended to s,p,d,f,g,h,i (or L) shells between 
2005-2013 by Graham Fletcher, Mike Schmidt, and Joe Ivanic.

    Any sp gradient integrals are done with Jose Sierra's 
modified version of the Gaussian80 code due to Schlegel.  
The spdfg gradient package consists of Michel Dupuis' Rys 
Polynomial code, and was adapted into GAMESS by Brett Bode 
at Iowa State University in 1994.

    The use of quantum fast multipole methods for avoiding 
long range integral evaluation in large molecules was 
programmed by Cheol Choi at Iowa State and at Kyungpook 
National University, and included in GAMESS in 2001.

    The Effective Core Potential (ECP) code goes back to 
Louis Kahn, with gradient modifications originally made by 
K.Kitaura, S.Obara, and K.Morokuma at IMS in Japan.  The 
code was adapted to HONDO by Stevens, Basch, and Krauss, 
from whence Kiet Nguyen adapted it to GAMESS at NDSU.  
Modifications for f functions were made by Drora Cohen and 
Brett Bode.  This code was completely rewritten to use 
spdfg basis sets, to exploit shell structure during 
integral evaluation, and to add the capability of analytic 
second derivatives by Brett Bode at ISU in 1997-1998.  Jose 
Sierra of Synstar removed the last few bugs from this in 

    The Model Core Potential (MCP) codes originate from the 
University of Alberta and the University of Kyushu.  MCP 
energy code was interfaced to GAMESS in 2003 by Mariusz 
Klobukowski (UofA).  Many model core potentials, and their 
associated valence basis sets, were added as a basis 
library by Mariusz in 2005.  Hirotoshi Mori and Eisaku 
Miyoshi (KyuDai) developed the nuclear gradient code for 
MCP with the assistance of a JSPS grant, and this code was 
included in GAMESS in March 2007.  The ZFK family of model 
core potentials for p-block elements was added to GAMESS by 
Toby Zeng in April 2010.

    Changes in the manner of entering the basis set, and 
the atomic coordinates (including Z-matrix forms) are due 
to Jan Jensen at North Dakota State University.

    The direct SCF implementation was done at NDSU, guided 
by a pilot code for the RHF case by Frank Jensen.

    The UHF code was taught to do high spin ROHF by John 
Montgomery at United Technologies in 1988, who extended the 
DIIS converger to ROHF and the one pair GVB case.  Jason 
Byrd and John Montgomery implemented the Constrained UHF 
method in 2013, note that CUHF is an alternative way to 
produce high spin ROHF results.

    The GVB code is a heavily modified version of GVBONE.

    Valence Bond theory calculations are implemented as a 
plug-in program named VB2000, authored by Jiabo Li, Brian 
Duke, and Roy McWeeny.  As of spring 2012, the VB2000 
source code is distributed within GAMESS source code 
distributions, and by default is compiled into GAMESS.  
Examples and program documentation are found in the vb2000 

    The SCF for Molecular Interactions option was added to 
GAMESS in 1997 by Antonino Famulari, during a summer visit 
from the University of Milan.  This two fragment code was 
replaced with a multi-fragment code from Maurizio Sironi of 
the University of Milan in 2004.

    The Direct Inversion in the Iterative Subspace (DIIS) 
convergence procedure was implemented by Brenda Lam (then 
at the University of Houston) in 1986, for RHF and UHF 
functions.  Additional GVB-DIIS cases were programmed by 
Galina Chaban at ISU.  The approximate second order SCF 
converger was implemented by Galina Chaban at Iowa State 
University in 1995, and was provided for RHF, ROHF, GVB, 
and MCSCF cases.  The FULLNR and FOCAS MCSCF convergers 
were contributed by Michel Dupuis from his HONDO program.  
A parallel implementation of the FULLNR converger was 
written by Graham Fletcher at Eloret in 2002.  The Jacobi 
orbital rotation scheme for MCSCF orbital optimization was 
written by Joe Ivanic and Klaus Ruedenberg at Iowa State 
University in 2001.

    The Ames Laboratory determinant full CI code was 
written by Joe Ivanic and Klaus Ruedenberg.  As befits code 
written by an Australian living in Iowa, it was interfaced 
to GAMESS during an extremely cordial visit to Australia 
National University in January 1998.  An update by Joe in 
October 2000 exploits Abelian point group symmetry.  A 
general CI program based on selected determinants was added 
by Joe and Klaus in July 2001.  After moving from Ames 
Laboratory at ISU to the Advanced Biomedical Computing 
Center of the National Cancer Institute-Frederick, Fort 
Detrick, Joe wrote a determinant based program for second 
order CI, in 2002.  In early 2003, Joe added the Occupation 
Restricted Multiple Active Space determinant CI program, 
again written at NCI.

    The GUGA CI is based on Brooks and Schaefer's unitary 
group program which was modified to run within GAMESS, 
using a Davidson eigenvector method written by Steve 

    Programming of the GUGA analytic CI gradient was done 
by Simon Webb in 1996 at Iowa State University.

    The CIS gradient program was written in 2003 by Simon 
Webb of the Advanced Biomedical Computing Center of the 
National Cancer Institute in Frederick.  Transition moments 
were added by Simon and Pooja Arora in June 2005.

    The sequential MP2 and UMP2 energy code was adapted 
from HONDO in 1994 by Nikita Matsunaga at ISU.  Nikita 
programmed the RMP open shell energy in 1992.  The ZAPT 
open shell energy was programmed by Rob Bell in 1999.  The 
serial closed shell MP2 gradient code is also from HONDO, 
and was adapted to GAMESS in 1995 by Simon Webb and Nikita 
Matsunaga.  In 1996, Simon Webb added the frozen core 
gradient option at ISU.  The parallel closed shell MP2 code 
is a descendant of work for GAMESS-UK by Graham Fletcher, 
Alistair Rendell, and Paul Sherwood at Daresbury.  This was 
adapted to GAMESS at ISU by Graham Fletcher in 1999.  
Serial and parallel codes for the spin unrestricted UMP2 
gradient were programmed by Christine Aikens at ISU, in 
2002.  Christine Aikens added a parallel spin-restricted 
open shell (ZAPT) gradient code in 2005.  Programs for 
parallel closed shell MP2 energy (2006) and gradient (2007) 
using disk storage were written by Kazuya Ishimura at the 
Institute for Molecular Science (IMS) in Okazaki.  The 
parallel Resolution of the Identity MP2 program by Michio 
Katouda, also from IMS, was added in 2010.

   Credits for multiconfigurational PT follow.  Haruyuki 
Nakano, then at the University of Tokyo, interfaced his 
multireference MCQDPT code (based on CSFs) to GAMESS during 
a 1996 visit to ISU, this is MRPT=MCQDPT.  Parallelization 
of the Tokyo multireference PT code was done by Hiroaki 
Umeda at Mie University, and included into GAMESS in 2001.  
A determinant based code which is equivalent to MRMP/MCQDPT 
was programmed in 2005 by Joe Ivanic of the National Cancer 
Institute, this is MRPT=DETMRPT.  In 2008, Haruyuki Nakano 
of the University of Kyushu contributed a general MCSCF 
reference quasi-degenerate perturbation theory code, 
MRPT=GMCPT, which is capable of treating various non-CAS 
references, including those of the ORMAS type.  In 2012, 
Luke Roskop of Iowa State University extended MRPT=DETMRPT 
to the case of ORMAS reference functions.

    The grid-free DFT energy and gradient code was written 
by Kurt Glaesemann at Iowa State University, starting from 
the code of Almlof and Zheng, adding four center overlap 
integrals, a gradient program, developing the auxiliary 
basis option, and adding some functionals.  This was 
included in GAMESS in 1999.

    The grid based DFT program was introduced in 2001 at 
the University of Tokyo, by Takao Tsuneda, Muneaki Kamiya, 
Susumu Yanagisawa, and Dmitri Fedorov. The original program 
is from Nevin Oliphant, Hideo Sekino, and Rod Bartlett at 
QTP.  Many improvements were made to this early program at 
U. Tokyo: using point group symmetry, switching from coarse 
to fine grids, functional development, and parallelization.  
Sarom Sok at ISU added many new functionals in 2007, 2008, 
and 2009, some with the help of Huub van Dam's density 
functional repository.  Sarom added the Truhlar group's 
meta-GGA M06 and M08 functionals in 2008 and 2009, using 
source code from U.Minnesota.  Roberto Peverati of the 
University of Zurich added Grimme's dispersion correction 
in 2008.  Roberto added "wB97" range separated GGA, "B97" 
style GGA and metaGGA, and B2-PLYP in 2009, and he added 
the M11 metaGGA family in spring 2011.  Federico Zahariev 
at ISU included the TPSS family of meta-GGAs in 2008 and 
2009.  Kiet Nguyen at Wright-Patterson AFB added CAM-B3LYP 
in 2009.  The HPTi project (Jean-Philippe Blaudeau, Shawn 
Brown, Mike Lasinksi, Nick Romero, Anthony Yau) enabled the 
use of Lebedev or Standard Grid-1 grids in April 2008, and 
Janssen's grids in May 2009.

    The time dependent DFT program originated in the group 
of Takao Tsuneda at the University of Tokyo, and was 
included into GAMESS in the fall of 2006 by Mahito Chiba at 
AIST in Tsukuba.  This group also included the "long range 
correction" option (aka "range separation") for both ground 
and excited states.  The analytic TD-DFT gradient for 
singlet excited states from a closed shell reference was 
added by Mahito Chiba in August 2007.  Mahito Chiba, in 
collaboration with Dmitri Fedorov, also developed FMO 
functionality in TD-DFT energies.  The TD-DFT energy for 
UHF ground states was added by Soohaeng Yoo at Iowa State, 
in February 2008.  Tamm/Dancoff approximation coding was 
done by Federico Zahariev at ISU in 2010.  The HPTi project 
parallelized the closed shell TD-DFT energy and gradient 
programs in April 2008.  Sarom Sok and Federico Zahariev 
have developed higher density derivatives for many 
functionals, allowing them to be used in TD-DFT energies 
and gradients.  Federico has also developed the corrections 
to the TD-DFT eigenvalue equation needed for meta-GGA 
excitation energies in 2010.  The two-photon absorption 
cross-sections were programmed by Federico Zahariev at ISU 
in spring 2012.

    TD-DFT solvation effects include EFP1 discrete 
solvation, added to the closed shell TD-DFT excitation 
energies in 2008 by Soohaeng Yoo, and to its gradient in 
2010 by Noriyuki Minezawa at ISU.  C-PCM solvent effects on 
TD-DFT closed shell excitation energies were added by 
Mahito Chiba in December 2008, with PCM modifications to 
this gradient by Yali Wang and Hui Li in November 2009.  
The combined TD-DFT/EFP/PCM solvation model was finished in 
November 2010 by Nandun Thellamurege and Hui Li at U. 

    Incorporation of enough MOPAC version 6 routines to run 
PM3, AM1, and MNDO calculations from within GAMESS was done 
by Jan Jensen at North Dakota State University.  The RM1 
parameterization was added by Melissa Gajewski in 2010, at 
U. Alberta.  Caspar Steinmann interfaced MOPAC to PCM in 
spring 2013, and also enabled parallel execution.

    The numerical force constant computation and normal 
mode analysis was adapted from Andy Komornicki's GRADSCF 
program, with decomposition of normal modes in internal 
coordinates written at NDSU by Jerry Boatz.

    The code for the analytic computation of RHF Hessians 
was contributed by Michel Dupuis of IBM from HONDO 7.  High 
and low spin restricted open shell CPHF code was written at 
NDSU in 1989.  The TCSCF CPHF code is the result of a 
collaboration between NDSU and John Montgomery, then at 
United Technologies, in 1990.  Analytic IR intensities and 
polarizabilities (during hessian runs) were programmed by 
Simon Webb at ISU in 1995.  Analytic Hessians for MCSCF 
wavefunctions based on determinants were coded, and enabled 
for parallel execution, by Tim Dudley at ISU, and included 
into GAMESS in April 2004, with a souped-up version added 
in March 2006.

    Code for Raman intensity prediction was written at 
Tokyo Metropolitan University in April 2000.

    The vibrational SCF and MP2 anharmonic frequency code 
for fundamental modes and overtones was written by Galina 
Chaban, Joon Jung, and Benny Gerber at U.California-Irvine 
and Hebrew University of Jerusalem, and included in GAMESS 
in 2000.  The solver was modified to perform degenerate 
perturbation theory for more accurate results by Nikita 
Matsunaga at Long Island University in 2001.

    Delocalized internal coordinates were implemented by 
Jim Shoemaker at the Air Force Institute of Technology in 
1997, and put online in GAMESS by Cheol Choi at ISU after 
further improvements in 1998.

    Most of the geometry search procedures (OPTIMIZE and 
SADPOINT) were developed by Frank Jensen of the University 
of Aarhus.  These methods are adapted to use GAMESS 
symmetry, and Cartesian or internal coordinates.  Numerical 
differentiation of the energy to obtain gradients and 
Hessians which may be used in OPTIMIZE or SADPOINT searches 
was programmed by Ryan Olson at ISU in 2003.  The MEX 
procedure for searching for minimum energy crossing points 
between two surfaces was programmed by Jeremy Harvey and 
Nikita Matsunaga, and finally included into GAMESS in 2006.  
The non-gradient optimization (so aptly named TRUDGE) was 
adapted from HONDO 7 by Mariusz Klobukowski at U.Alberta, 
this may be more interesting for its exponent optimization 

    The intrinsic reaction coordinate pathfinder was 
written at North Dakota State University, and modified 
later for new integration methods by Kim Baldridge.  The 
Gonzales-Schelegel IRC stepper was incorporated by Shujun 
Su at Iowa State, based on pilot code from Frank Jensen.

    The code for the Dynamic Reaction Coordinate was 
developed by Tetsuya Taketsugu at Ochanomizu U. and U. of 
Tokyo, and added to GAMESS by him at ISU in 1994.

    The two algorithms for tracing gradient extremals were 
programmed by Frank Jensen, now at the University of 

    The program for Monte Carlo generation of trial 
structures along with a simulated annealing protocol was 
written by Paul Day at Wright-Patterson Air Force Base. 
Modifications to this were made by Pradipta Bandyopadhyay 
at ISU, and the code was included in 2001.

    The surface scanning option was implemented by Richard 
Muller at the University of Southern California.

    Static polarizabilities for any type of energy value 
are bases on a code from Henry Kurtz of the University of 
Memphis.  This uses a numerical differentiation based on 
application of finite electric fields.  The program was 
added in 1992, and was modified by Sanka Ghosh to produce 
all tensor components in 2005.

    Henry Kurtz' program for the fully analytic calculation 
of static and frequency dependent polarizabilities for NLO 
properties for closed shell systems was included in 1994, 
based on a MOPAC implementation by Prakashan Korambath at 
U. Memphis.

    An extended TDHF package for the analytic computation 
of static and frequency dependent polarizabilities, and 
also their nuclear derivatives, plus Raman and hyperRaman 
spectra prediction was written by Olivier Quinet and Benoit 
Champagne at the Facultes Universitaires Notre-Dame de la 
Paix, and coworker Bernard Kirtman at UC-Santa Barbara.  
Financial support for this was provided by Belgium.  This 
package was added to GAMESS in February 2005.

   Ivana Adamovic programmed the imaginary frequency 
polarizability computation for closed shell functions in 
2005, at ISU.

    Edmiston-Ruedenberg energy localization is done with a 
version of the ALIS program "LOCL", modified at NDSU to run 
inside GAMESS.  Foster-Boys localization is based on a 
highly modified version of QCPE program 354 by D.Boerth, 
J.A.Hasmall, and A.Streitweiser.  John Montgomery 
implemented the Pipek/Mezey population localization.  The 
LCD SCF decomposition and the MP2 decomposition were 
written by Jan Jensen at Iowa State in 1994.

    Point Determined Charges were implemented by Mark 
Spackman at the University of New England, Australia.

    The Morokuma decomposition was implemented by Wei Chen 
at Iowa State University, in 1995.  The Localized Molecular 
Orbital Energy Decomposition Analysis was implemented by 
Peifeng Su and Hui Li at the University of Nebraska in 

    The radiative transition moment and effective nuclear 
charge spin-orbit coupling modules were written by Shiro 
Koseki at North Dakota State University in 1990.

    Relativistic effects include spin-orbit coupling and 
spin-independent scalar relativity, whose all-electron 
treatments are described next.  As noted above, ECP and MCP 
calculations are efficient ways of treating scalar 
relativity.  Spin-orbit effects for ECP can be treated by 
Shiro Koseki's effective nuclear charge paramters.  Spin-
orbit effects for MCP can be treated by Toby Zeng, Dmitri 
Fedorov, and Mariusz Klobukowski's ZFK potentials. 

    The full Breit-Pauli spin-orbit coupling integral 
package was written by Thomas Furlani.  This code was 
incorporated into GAMESS by Dmitri Fedorov at Iowa State 
University in 1997, who generalized the spin-orbit coupling 
matrix element code generously provided by Thomas Furlani 
(restricted to an active space of two electrons in two 
orbitals), with assistance from visits to ISU by Thomas 
Furlani and Shiro Koseki.  Dmitri Fedorov has since 
generalized the full two electron approach to allow for any 
spins, for more than two spin multiplicities at a time, and 
a partial treatment of the the two electron terms that runs 
in time similar to the one electron operator.  Space and 
spin symmetries are exploited to speed up the runs.  Dmitri 
Fedorov programmed the SO-MCQDPT options at the University 
of Tokyo in 2001.  Density matrix calculation for spin-
orbit coupled states was programmed by Toby Zeng and 
Mariusz Klobukowski at the University of Alberta, and added 
to GAMESS in April 2010.

    Inclusion of scalar relativistic effects by the 
Relativistic scheme of Elimination of Small Components 
(RESC) method was developed by Takahito Nakajima and 
Kimihiko Hirao at the University of Tokyo.  This code was 
written by Takahito Nakajima and consequently adapted into 
GAMESS by Dmitri Fedorov, who extended the methodology in 
March 2000 to the computation of gradients.  These workers 
programmed the 2nd and 3rd order Douglas-Kroll (DK) 
correction, adding it to GAMESS in 2003.  Incorporation of 
scalar relativistic corrections to an infinite order two-
component (IOTC) transformation was added in September 
2010, by Maria Barysz of Nicholas Copernicus University - 
this is effectively infinite order DK.  Yuya Nakajima, 
Junji Seino, and Hiromi Nakai at Waseda University 
developed the 'local unitary transformation' variant of 
IOTC (LUT-IOTC), to control both the time requirements and 
the accuracy of energy and gradients, which was included in 
GAMESS in the summer of 2015.  The ESC methods transform 
only the 1e- integrals (and their derivatives), and are 
computationally efficient.  The Sapporo basis set family 
which is optimized for scalar relativity were kindly 
provided by Takeshi Noro of Hokkaido University.

    The various ESC-type scalar relativity schemes can also 
be applied to the spin-orbit coupling correction, by 
applying the 1st order Douglas/Kroll correction after RESC, 
DKH, and full IOTC.  These methods apply the DK1 
transformation to the 1e- part of the spin-orbit operator, 
usually yielding more reliable results.

    The Normalized Elimination of Small Components (NESC) 
was programmed by Dmitri Fedorov at ISU and the University 
of Tokyo.  Special thanks are due to Kenneth Dyall for his 
assistance in providing check values.  Extension of NESC to 
include gradient computation was also done by Dmitri.

    Development of the EFP method began in the group of 
Walt Stevens at NIST's Center for Advanced Research in 
Biotechnology (CARB) in 1988.  Walt is the originator of 
this method, and has provided both guidance and some early 
financial support to ISU for its continued development. 
Mark Gordon's group's participation began in 1989-90 as 
discussions during a year Mark spent in the DC area, and 
became more serious in 1991 with a visit by Jan Jensen to 
CARB.  At this time the method worked for the energy, and 
gradient with respect to the ab initio nuclei, for one 
fragment only.  Jan has assisted with most aspects of the 
multi-fragment development since.  Paul Day at NDSU and ISU 
derived and implemented the gradient with respect to 
fragments, and programmed EFP geometry optimization, from 
1992-1994.  Wei Chen at ISU debugged many parts of the EFP 
energy and gradient, developed the code for following IRCs, 
improved geometry searches, and fitted much more accurate 
repulsive potentials, from 1995-1996.  Simon Webb at ISU 
programmed the current self-consistency process for the 
induced dipoles in 1994.  The EFP method was sufficiently 
developed, tested, and described, to be released in 
September 1996, with an RHF level potential for water.  
Code for charge penetration was added by Mark Freitag in 
2001, and made numerically stabile by Lyuda Slipchenko in 
2006.  Ivana Adamovic included a DFT level EFP for water in 
2002.  Parallelization of the EFP codes was done by Heather 
Netzloff in 2005.

    The second EFP theory (called EFP2) was begun in 1996 
by Jan Jensen, who programmed an analytic formula for the 
exchange repulsion.  Hui Li replaced this with a faster, 
more accurate code in 2005.  Ivana Adamovic programmed a 
dispersion term for EFP2 in 2005.  Hui Li added the charge 
transfer term for EFP2 in 2005.

    Two other methods using the EFP model are available.  A 
combination of EFP + PCM energies (an onion-like solution 
model) was programmed by Pradipta Bandyopadhyay in 2000.  
The use of EFPs to model biological systems, including a 
boundary across a covalent bond, was coded at the 
University of Iowa in 2000, by Jan Jensen, Visvaldas 
Kairys, and Hui Li.

    The SCRF solvent model was implemented by Dave Garmer 
at CARB, and was adapted to GAMESS by Jan Jensen and Simon 
Webb at Iowa State University.

    The COSMO model was developed by Andreas Klamt and Kim 
Baldridge, starting at the San Diego Supercomputer Center, 
and later at University of Zurich.  It was included into 
GAMESS by Laura Brovold in March 2000 during a visit to 
Ames.  Subsequent additions were made by Yohann Potier and 
Roberto Peverati, at the University of Zurich, and included 
in GAMESS in June 2010.

    The PCM code originated in the group of Jacopo Tomasi 
at the University of Pisa.  Benedetta Mennucci was 
instrumental in interfacing the original D-PCM code to 
GAMESS in 1997, and answering many technical questions 
about the code, the methodology, and the documentation.  In 
2000, Benedetta Menucci provided code implementing an 
improved IEF solver for the PCM surface charges.  The 
changes to implement iterative solution of the PCM 
equations for large molecules, and to provide an accurate 
nuclear gradient were carried out by Hui Li and Jan Jensen 
at the University of Iowa in 2001-2004, along with the 
parallelization.  This included implementation of two new 
surface tessellation schemes, GEPOL-AS and GEPOL-RT.  Hui 
and Jan also implemented the Conductor-PCM method, and 
extended the PCM methodology to all types of SCF functions. 
Hui Li's research group at the University of Nebraska 
implemented the following improvements: FIXPVA tessellation 
with smooth switching functions for reliable geometry 
optimizations (Peifeng Su, 2008), extension of FIXPVA to 
cavitation, repulsion, and dispersion (2009), heterogenous 
CPCM (Dejun Si, 2009), closed shell PCM/TDDFT gradients 
(Yali Wang, 2009), closed shell PCM/MP2 gradients (Dejun 
Si, 2010), open shell PCM/MP2 gradients (Dejun Si, 
September 2010), and combined EFP/PCM solvation for all 
single reference MP2 gradients (Nandun Thellamurege and 
Dejun Si, November 2010).  The SMD modifications to the PCM 
model are due to Alek Marenich, Junjun Liu, Chang-Guo Zhan, 
Christopher Cramer, and Don Truhlar at U. Minnesota 
(November 2010).

    The Surface and Volume Polarization for Electrostatics 
continuum solvation model is written by Dan Chipman of 
Notre Dame University, using several integral routines 
written by Michel Dupuis for the SVP model included in 
HONDO.  The SVP model was added to GAMESS in June 2005.

    The SIMOMM model for surface chemistry is based on the 
Tinker program of Jay Ponder's group, and is available as a 
plug-in option.  The treatment is QM embedded in a MM 
background.  The coding for this was done by Jim Shoemaker 
at the Air Force Institute of Technology, and finished by 
Cheol Ho Choi at ISU.  The interface to GAMESS was 
completed in 1998.

    The Coupled-Cluster (CC) and Equation of Motion 
Coupled-Cluster (EOMCC) programs included in GAMESS are due 
to Piotr Piecuch, Karol Kowalski, Marta Wloch, Jeffrey 
Gour, and Jesse Lutz of Michigan State University (MSU), 
and Stanislaw A. Kucharski and Monika Musial of the 
University of Silesia.  In addition to a number of standard 
CC and EOMCC methods, including the older CCSD, CCSD(T), 
and EOMCCSD approaches, the CC codes incorporated in GAMESS 
are capable of performing renormalized (R) and completely 
renormalized (CR) CCSD[T] and CCSD(T) calculations for the 
ground state, the ground-state calculations employing the 
rigorously size extensive completely renormalized non-
iterative triples CR-CCSD(T)_L = CR-CC(2,3) approach.  The 
combined corrections due to triply and quadruply excited 
clusters are available in the factorized forms of the 
CCSD(TQ), renormalized CCSD(TQ), and completely 
renormalized CCSD(TQ) models.  For excited states, 
completely renormalized EOMCCSD(T) (CR-EOMCCSD(T)) and EOM-
CR-CC(23) calculations are possible.  Electron attachment 
and detachments (including excitations) are available as 
IP-EOM and EA-CC methods.  The one-body reduced density 
matrices, dipole moments, transition dipole moments, and 
oscillator strengths are available at the CCSD and EOMCCSD 
levels, for RHF.  The ground-state CC, R-CC, and CR-CC 
programs were initially incorporated into GAMESS in May 
2002.  The excited-state EOMCC and CR-EOMCC programs were 
incorporated in April 2004.  Quadruples corrections and 
CCSD/EOM-CCSD density matrices were added in June 2005.  
The CR-CC(2,3) ground-state approach was added in January 
2006.  Parallel computation of CCSD and CCSD(T) for closed 
shell references was enabled by Ryan Olson and Jonathan 
Bentz at Iowa State, in October 2006.  Open shell CCSD and 
CR-CCL based on ROHF reference orbitals was added in May 
2007.  CR-EOML and IP-EOMCC2/EA-EOMCC2 were included in 
October 2009, and active triples for IP/EA calculations 
were finished in September 2010.  Open shell reference EOM-
CCSD was completed in October 2011.  All of these programs 
were developed with the support of the US Department of 
Energy, Office of Basic Energy Sciences, SciDAC 
Computational Chemistry Program and the Chemical Sciences, 
Geosciences, and Biosciences Division.  Additional support 
has been provided by the NSF's ITR program and the Alfred 
P. Sloan Foundation.

    The GIAO computation of NMR properties for closed shell 
molecules was programmed by Mark Freitag at Iowa State 
University, and included in GAMESS in November 2003.

    The code for the Fragment Molecular Orbital (FMO) 
method incorporated and distributed as a part of the 
standard GAMESS package since May 2004 is being developed 
at the National Institute of Advanced Industrial Science 
and Technology (AIST, Japan) by Dmitri Fedorov and Kazuo 
Kitaura.  The FMO method is the successor of the EDA scheme 
developed by K. Kitaura and K. Morokuma (known in GAMESS as 
Morokuma-Kitaura decomposition), however, the FMO code was 
written independently.  In GAMESS only the full FMO method 
is incorporated whereas in the literature one can also find 
a simplified approach suited for molecular crystals.  Since 
"FMO" is also used to mean "Frontier Molecular Orbitals" 
and the concept of fragments is also introduced in the EFP 
method (see above), it is stressed here that the FMO method 
bears no relation to either of the two methods, that is to 
say, it is independent of the two, but might be combined 
with either of them in the future just as EFPs are used in 
e.g. RHF.

    The Nuclear Electron Orbital (NEO) plug-in code is 
developed in the group of Sharon Hammes-Schiffer at 
Pennsylvania State University, with programming by Simon P. 
Webb, Tzvetelin Iordanov, Mike Pak, and Chet Swalina.  The 
initial release in 2006 permits HF and MP2 level treatment 
of nuclear wavefunctions.

   The elongation method, coded and linked to the standard 
GAMESS package since April 2006, is a method to mimic the 
mechanism of the polymerization/copolymerization in 
experiment.  Attacking monomers approach a starting chain, 
one by one and the electron structure is determined in the 
interactive region.  Thus, one can perform very efficient 
calculations for the electronic structure of huge random 
(aperiodic) polymers.  The elongation method was first 
proposed by A. Imamura and Y. Aoki in 1990s.  The present 
code was written by Feng Long Gu, Jacek Korchowiec, Marcin 
Makowski, and Yuriko Aoki at the Department of Molecular 
and Material Sciences, Faculty of Engineering Sciences, at 
Kyushu University.

    The Divide and Conquer SCF, MP2, and CCSD programs were 
developed at Waseda University, and were included in GAMESS 
in January 2009.  The code was written by Masato Kobayashi, 
Tomoko Akama, and Hiromi Nakai.

    The quantum chemistry polarizable force field program 
(QuanPol) was written by Hui Li, Nandun Thellamurege and 
Dejun Si at the University of Nebraska-Lincoln. These 
authors finished the initial implementation of QuanPol in 
August 2011, under an NSF support.

    Many of the options just mentioned have been programmed 
to run in parallel, on systems ranging from Linux clusters 
to high-end parallel systems.  The same software interface 
sits between the quantum chemistry in GAMESS and any such 
hardware, namely the Distributed Data Interface (DDI).  
This implements a mechanism for using the memory of the 
entire system to store the large arrays appearing in 
quantum chemistry codes.  The first version of DDI was due 
to Graham Fletcher and Mike Schmidt, introduced in 1999. 
The second version of DDI is due to Ryan Olson of ISU, and 
Alistair Rendell of the Australian National University, and 
includes optimizations for SMP systems, along with other 
improvements for some high end systems.  The second version 
also includes the 'group' scheme, presently used only in 
FMO jobs.  This DDI was introduced into GAMESS in April 
2004, with public release in June 2004.

Distribution Policy

    To get a copy, please fill out the application form 
available at 
this site.

    Persons receiving copies of GAMESS are requested to 
acknowledge that they will not make copies of GAMESS for 
use at other sites, or incorporate any portion of GAMESS 
into any other program, without receiving permission to do 
so from ISU.  If you know anyone who wants a copy of 
GAMESS, please refer them to the web site above, for the 
most up to date version available.

    No large program can ever be guaranteed to be free of 
bugs, and GAMESS is no exception.  If you would like to 
receive an updated version (fewer bugs, and with new 
capabilities), simply return to the web site mentioned.  
You should probably allow a half year or so to pass for 
enough significant changes to accumulate.  The web page 
always contains a short synopsis of the most recent 

Input Philosophy

    Input to GAMESS may be in upper or lower case.  All
input groups begin with a $ sign in column 2, meaning
exactly column 2 or else it is not detected, followed by
a name identifying that group.  There are three types of
input groups in GAMESS:

    1.  A pseudo-namelist, free format, keyword driven
group.  Almost all input groups fall into this first

    2.  A free format group which does not use keywords.
The first line of these will contain only the group name,
followed by several lines of positional data usually with
no keywords, and a last line containing " $END" only.
The only members of this category are $DATA, $ECP, $MCP,
$GCILST, $POINTS, $STONE, and the EFP related data $EFRAG,

    3.  Formatted data.  This data is NEVER typed by the
user, but rather is generated in the correct format by
some earlier GAMESS run.  Like category 2, the first line
contains only the group name, and the last line is a
separate $END line.

    Type 1 groups may have keyword input on the same line
as the group name, and the $END may appear anywhere.

    Because each group has a unique name, the groups may
be given in any order desired.  In fact, multiple
occurrences of category 1 groups are permissible.

                       * * *

    Most of the groups can be omitted if the program
defaults are adequate.  An exception is $DATA, which is
always required.  A typical free format $DATA group is

STO-3G test case for water
CNV      2

OXYGEN       8.0
    STO  3

HYDROGEN     1.0    -0.758       0.0     0.545
    STO  3


    Here, position is important.  For example, the atom
name must be followed by the nuclear charge and then the
x,y,z coordinates.  Note that missing values will be read
as zero, so that the oxygen is placed at the origin.
The zero Y coordinate must be given for the hydrogen,
so that the final number is taken as Z.

    The free format scanner code used to read $DATA is
adapted from the ALIS program, and is described in the
documentation for the graphics programs which accompany
GAMESS.  Note that the characters ;>!  mean something
special to the free format scanner, and so use of these
characters in $DATA and $ECP should probably be avoided.

    Because the default type of calculation is a single
point (geometry) closed shell SCF, the $DATA group shown
is the only input required to do a RHF/STO-3G water

                       * * *

    As mentioned, the most common type of input is a
namelist-like, keyword driven, free format group.  These
groups must begin with the $ sign in column 2, but have no
further format restrictions.  You are not allowed to
abbreviate the keywords, or any string value they might
expect.  They are terminated by a $END string, appearing
anywhere.  The groups may extend over more than one
physical card.  In fact, you can give a particular group
more than once, as multiple occurrences will be found and
processed.  We can rewrite the STO-3G water calculation
using the keyword groups $CONTRL and $BASIS as

Cnv    2

Oxygen       8.0     0.0         0.0     0.0
Hydrogen     1.0    -0.758       0.0     0.545

    Keywords may expect logical, integer, floating point,
or string values.  Group names and keywords never exceed 6
characters.  String values assigned to keywords never
exceed 8 characters.  Spaces or commas may be used to
separate items:


    Floating point numbers need not include the decimal,
and may be given in exponential form, i.e. TIMLIM=30,
TIMLIM=3.E1, and TIMLIM=3.0D+01 are all equivalent.

    Numerical values follow the FORTRAN variable name
convention.  All keywords which expect an integer value
begin with the letters I-N, and all keywords which expect
a floating point value begin with A-H or O-Z.  String or
logical keywords may begin with any letter.

    Some keyword variables are actually arrays.  Array
elements are entered by specifying the desired subscript:

 $SCF NO(1)=1 NO(2)=1 $END

    When contiguous array elements are given this may be
given in a shorter form:

 $SCF NO(1)=1,1 $END

    When just one value is given to the first element of
an array, the subscript may be omitted:

 $SCF NO=1 NO(2)=1 $END

    Logical variables can be .TRUE. or .FALSE. or .T.
or .F.  The periods are required.

    The program rewinds the input file before searching
for the namelist group it needs.  This means that the
order in which the namelist groups are given is
immaterial, and that comment cards may be placed between
namelist groups.

    Furthermore, the input file is read all the way
through for each free-form namelist so multiple occurrences
will be processed, although only the LAST occurrence of a
variable will be accepted.  Comment fields within a
free-form namelist group are turned on and off by an
exclamation point (!).  Comments may also be placed after
the $END's of free format namelist groups.  Usually,
comments are placed in between groups,

molecule goes here...

    The second $CONTRL is not read, because it does not
have a blank and a $ in the first two columns.  Here a
careful user has executed a CHECK job, and is now running
the real calculation.  The CHECK card is now just a
comment line.

                       * * *

    The final form of input is the fixed format group.
These groups must be given IN CAPITAL LETTERS only!  This
includes the beginning $NAME and closing $END cards, as
well as the group contents.  The formatted groups are
$VEC, $HESS, $GRAD, $DIPDR, and $VIB.  Each of these is
produced by some earlier GAMESS run, in exactly the
correct format for reuse.  Thus, the format by which they
are read is not documented in section 2 of this manual.

                       * * *

    Each group is described in the Input Description
section.  Fixed format groups are indicated as such, and
the conditions for which each group is required and/or
relevant are stated.

    There are a number of examples of GAMESS input given
in the Input Examples section of this manual.

Input Checking

    Because some of the data in the input file may not be
processed until well into a lengthy run, a facility to
check the validity of the input has been provided.  If
EXETYP=CHECK is specified in the $CONTRL group, GAMESS
will run without doing much real work so that all the
input sections can be executed and the data checked for
correct syntax and validity to the extent possible.  The
one-electron integrals are evaluated and the distinct row
table is generated.  Problems involving insufficient
memory can be identified at this stage.  To help avoid the
inadvertent absence of data, which may result in the
inappropriate use of default values, GAMESS will report
the absence of any control group it tries to read in CHECK
mode.  This is of some value in determining which control
groups are applicable to a particular problem.

    The use of EXETYP=CHECK is HIGHLY recommended for the
initial execution of a new problem.

Program Limitations

    GAMESS can use an arbitrary Gaussian basis of spdfghi 
type for computation of the energy, spdfg for analytic 
nuclear gradients, or spd for analytic nuclear hessians, in 
the gas phase.  Additional restrictions apply, for example, 
if solvent models, core potentials, scalar or spin-orbit 
relativistic effects are used.

    This program is limited to a total of 2,000 atoms.  The 
total number of symmetry unique basis set shells cannot 
exceed 5,000, containing no more than 20,000 Gaussian 
primitives.  Each contraction must contain no more than 30 
Gaussians.  The total number of contracted basis functions, 
or AOs, cannot exceed 8192.  You may use up to 1050 
effective fragments, of at most 5 types, containing no more 
than 2000 multipole/polarizability/other expansion points.

    In practice, you will probably run out of CPU time or 
disk storage before you encounter any of these limitations.  
See Section 5 of this manual for information about changing 
any of these limits, or minimizing program memory use.

    Except for these limits, the program is basically 
dimension limitation free.  Memory allocations other than 
these limits are dynamic, from the storage requested by the 

Restart Capability

    The program checks for CPU time, and will stop if time 
is running short.  Restart data are printed and punched out 
automatically, so the run can be restarted where it left 

    At present all SCF modules will place the current 
orbitals on the punch file if the maximum number of 
iterations is reached.  These orbitals may be used in 
conjunction with the GUESS=MOREAD option to restart the 
iterations where they quit.  Also, if the TIMLIM option is 
used to specify a time limit just slightly less than the 
job's batch time limit, GAMESS will halt if there is 
insufficient time to complete another full iteration, and 
the current orbitals will be punched.

    When searching for equilibrium geometries or saddle 
points, if time runs short, or the maximum number of steps 
is exceeded, the updated hessian matrix is punched for 
restart.  Optimization runs can also be restarted with the 
direct access file DICTNRY.  See $STATPT for details.

    Force constant matrix runs can be restarted from cards.  
See the $VIB group for details.

    The two electron integrals may be reused.  The Newton-
Raphson formula tape for MCSCF runs can be saved and 

                       * * * *

    The binary file restart options are rarely used, and so 
may not work well (or at all).  Restarts which change the 
card input (adding a partially converged $VEC, or updating 
the coordinates in $DATA, etc.) are far more likely to be 
successful than restarts from the DAF file.

Updated on July 7, 2017