$BASIS group          (optional)                                                
                                                                                
    This group allows certain standard basis sets to be                         
easily requested.  Basis sets are specified by:                                 
                                                                                
a) GBASIS plus optional supplementations such as NDFUNC,                        
b) BASNAM to read custom basis sets from your input,                            
c) EXTFIL to read custom bases from an external file,                           
d) or omit this group entirely, and give the basis set in                       
   the $DATA input, which is completely general.                                
                                                                                
GBASIS requests various Gaussian basis sets.  These include                     
options for effective core and model core potentials.                           
                                                                                
Rather oddly, GBASIS also can select semi-empirical models,                     
and in that case requests the Slater-type orbitals for the                      
MOPAC-type calculation.                                                         
                                                                                
Note: The first two groups of GBASIS keywords below (except                     
G3L and G3LX) define only the basic functions, without any                      
polarization functions and/or diffuse functions.  For                           
example, main group elements have the basic functions for                       
their s,p valence orbitals.  Polarization and/or diffuse                        
supplements are added separately to these GBASIS values,                        
with keywords NPFUNC, NDFUNC, NFFUNC, DIFFS, DIFFSP, POLAR,                     
SPLIT2, and SPLIT3, which are defined at the end of this                        
input group.                                                                    
                                                                                
GBASIS = STO  - Pople's STO-NG minimal basis set.                               
                Available H-Xe, for NGAUSS=2,3,4,5,6.                           
       = N21  - Pople's N-21G split valence basis set.                          
                Available H-Xe, for NGAUSS=3.                                   
                Available H-Ar, for NGAUSS=6.                                   
       = N31  - Pople's N-31G split valence basis set.                          
                Available H-Ne,P-Cl for NGAUSS=4.                               
                Available H-He,C-F for NGAUSS=5.                                
                Available H-Kr, for NGAUSS=6, note that the                     
                  bases for K,Ca,Ga-Kr were changed 9/2006.                     
       = N311 - Pople's "triple split" N-311G basis set.                        
                Available H-Ne, for NGAUSS=6.                                   
                Selecting N311 implies MC for Na-Ar.                            
       = G3L  - Pople's G3MP2Large basis set, for H-Kr.                         
       = G3LX - Pople's G3MP2LargeXP basis set, for H-Kr.                       
                                                                                
NGAUSS = the number of Gaussians (N).   This parameter                          
         pertains to GBASIS=STO, N21, N31, or N311.                             
                                                                                
GBASIS = MINI - Huzinaga's 3 gaussian minimal basis set.                        
                Available H-Rn.                                                 
       = MIDI - Huzinaga's 21 split valence basis set.                          
                Available H-Rn.                                                 
       = DZV  - "double zeta valence" basis set.                                
                a synonym for DH for H,Li,Be-Ne,Al-Cl.                          
                (14s,9p,3d)/[5s,3p,1d] for K-Ca.                                
                (14s,11p,5d/[6s,4p,1d] for Ga-Kr.                               
       = DH   - Dunning/Hay "double zeta" basis set.                            
                (3s)/[2s] for H.                                                
                (9s,4p)/[3s,2p] for Li.                                         
                (9s,5p)/[3s,2p] for Be-Ne.                                      
                (11s,7p)/[6s,4p] for Al-Cl.                                     
       = TZV  - "triple zeta valence" basis set.                                
                (5s)/[3s] for H.                                                
                (10s,3p)/[4s,3p] for Li.                                        
                (10s,6p)/[5s,3p] for Be-Ne.                                     
                a synonym for MC for Na-Ar.                                     
                (14s,9p)/[8s,4p] for K-Ca.                                      
                (14s,11p,6d)/[10s,8p,3d] for Sc-Zn.                             
       = MC   - McLean/Chandler "triple split" basis.                           
                (12s,9p)/[6s,5p] for Na-Ar.                                     
                Selecting MC implies 6-311G for H-Ne.                           
       = MINIX  The minimal basis set for HF-3C, but no                         
                energy corrections added.                                       
       = HF-3C  The minimal basis set MINIX and three                           
                add-on energy corrections (3c). These                           
                three corrections are D3(BJ), GCP and SRB.                      
                See $DFT's dispersion corrections.                              
                                                                                
* * systematic basis set families * * *                                         
                                                                                
These four families provide a hierachy of basis sets                            
approaching the complete basis set limits.  These families                      
include relevant polarization and diffuse augmentations, as                     
indicated in their names.                                                       
                                                                                
GBASIS = CCn  - Dunning-type Correlation Consistent basis                       
                sets, officially called cc-pVnZ.                                
                Use n = D,T,Q,5,6 to indicate the level of                      
                polarization.                                                   
                Available for H-He, Li-Ne, Na-Ar, Ca, Ga-Kr                     
                and for Sc-Zn for n=T,Q.                                        
       = ACCn - As CCn, but augmented with a set of diffuse                     
                functions, e.g. aug-cc-pVnZ.                                    
                Availability is the same as CCn.                                
       = CCnC - As CCn, but augmented with tight functions                      
                for recovering core and core-valence                            
                correlation, e.g. cc-pCVnZ.                                     
                            Available H-Ar for n=D,T,Q, also n=5 for H-Ne.      
       = ACCnC- As CCn, augmented with diffuse as well as                       
                CCnC's tight functions, e.g. aug-cc-pCVnZ.                      
                Availability is the same as CCnC.                               
       = CCnWC  the omega form of CCnC, e.g. cc-pwCVnZ, for                     
                H-Ar, for n=T only.  CCnWC's tight                              
                functions are considered superior to CCnC's                     
                for recovery of core/valence correlation.                       
       = ACCnWC augmented form of CCnWC: aug-cc-pwCVnZ.                         
                        See extended notes below!                               
                                                                                
       = PCseg-n -  Polarization Consistent basis sets.                         
                    n = 0,1,2,3,4 indicates the level of                        
                    polarization. (n=0 is unpolarized, n=1                      
                    is ~DZP, n=2 is ~TZ2P, etc.). These                         
                    provide a hierarchy of basis sets                           
                    suitable for DFT and HF calculations.                       
                    Available for H-Kr.                                         
       = APCseg-n - These are the PCseg-n bases, with                           
                    diffuse augmentation.                                       
                        See extended notes below!                               
                                                                                
                       Sapporo valence basis sets:                              
       = SPK-nZP  - Sapporo family of non-relativistic                          
                    bases, n=D,T,Q, available H-Xe                              
       = SPK-AnZP - diffuse augmentation of the above.                          
       = SPKrnZP  - Sapporo family of relativistic bases                        
                    n=D,T,Q, available H-Xe.  These should                      
                    be used only with a relativistic                            
                    transformation of the integrals, such                       
                    as RELWFN=LUT-IOTC.                                         
       = SPKrAnZP - diffuse augmentation of the above.                          
                       See extended notes below!                                
                                                                                
                       Sapporo core/valence basis sets:                         
       = SPK-nZC  - Sapporo family of non-relativistic                          
                    bases, n=D,T,Q, available H-Xe                              
       = SPK-nZCD - diffuse augmentation of the above.                          
       = SPKrnZC  - Sapporo family of relativistic bases                        
                    n=D,T,Q, available H-Rn.                                    
                    To be used only with a relativistic                         
                    transformation of the integrals, such                       
                    as RELWFN=LUT-IOTC.                                         
       = SPKrnZCD - diffuse augmentation of the above.                          
                        See extended notes below!                               
                                                                                
       = KTZV - Karlsruhe valence triple zeta basis, as                         
                developed by Prof.Ahlrichs, see REFS.DOC.                       
       = KTZVP- Karlsruhe valence triple zeta basis with a                      
                set of single polarization (P).                                 
       = KTZVPP-Karlsruhe valence triple zeta basis with a                      
                set of double polarization (PP).                                
                The Karlsruhe sets are provided for H-Ar.                       
                                                                                
Normally these families are used as spherical harmonics,                        
see ISPHER=1 in $CONTRL.  Failure to set ISPHER=1 will                          
result in discrepancies in energy values compared to the                        
literature or other programs, difficulties in converging                        
SCF/DFT, CC, CI, and/or response equation iterations, and                       
longer run times due to retention of unimportant MOs.  The                      
calculations will refuse to run without ISPHER being set.                       
                                                                                
Important note about the PCseg basis set family:                                
                                                                                
1. These should be used only in spherical harmonic form.                        
2. The PCn basis sets included in GAMESS versions prior to                      
March 2014 were generally contracted, but were replaced by                      
computationally more efficient segmented contractions, and                      
renamed to PCseg-n. The segemented contractions have the                        
same or slightly better accuracy (especially for n=0) as                        
the original PCn bases, which are no longer available.                          
                                                                                
Important notes about the CC basis set family:                                  
                                                                                
1. These should be used only in spherical harmonic form.                        
2. The CC5 and CC6 basis sets (and corresponding augmented                      
versions) contain h-functions, and CC6 also contains i-                         
functions.  As of January 2013, GAMESS integral code can                        
correctly use h & i functions, so these three call up the                       
true basis sets.  Prior to January 2013, GAMESS' integral                       
codes was restricted to g-functions, so these three                             
truncated away any h & i functions, to spdfg subsets, and                       
therefore were not the true basis sets.                                         
3. Note that the CC basis sets are generally contracted,                        
which GAMESS can only handle by replicating the primitive                       
basis functions, leading to a less than optimum performance                     
in AO integral evaluation.                                                      
4. The implementation of the cc-pVnZ and cc-pCVnZ basis                         
sets for Na-Ar include one additional tight d-function,                         
producing the so-called cc-pV(n+d)Z and cc-pV(n+d)Z sets,                       
which are known to improve results (see J.Chem.Phys. 114,                       
9244(2001) and Theoret.Chem.Acc. 120, 119(2008)).  These                        
tight d versions are invoked by GBASIS=CCn or CCnC (and                         
also their augmented counterparts ACCn or ACC).  This means                     
the old (and less accurate) basis sets without the tight                        
d's are not available for Na-Ar.                                                
5. Alkali and alkali earth basis sets (Li,Be,Na,Mg) were                        
changed April 2013 so that regular, diffuse, tight d (for                       
Na/Mg), core/valence, and weighted core/valence sets agree                      
with their official publication: Theor. Chem. Acc. 128,                         
69(2011).                                                                       
6. In case you are interested in scalar relativistic                            
effects, the CCT-DK and CCQ-DK sets optimized for use with                      
Douglas/Kroll are available for Sc-Kr.  These will be used                      
if you type GBASIS=CCT or CCQ along with RELWFN=RESC, DK,                       
IOTC, or LUT-IOTC, while using NR sets for elements lighter                     
than Sc.  DK versions of ACCD or ACCT are available for Sc-                     
Zn (but not for the rest of the row, Ga-Kr).                                    
                                                                                
Notes about the Sapporo basis set family:                                       
                                                                                
1. SPK is the international airport city code for Sapporo.                      
2. These should be used only in spherical harmonic form.                        
3. The relativistic core/valence sets are available for all                     
atoms including the 6th row of the periodic table (H-Rn).                       
4. It is extremely illogical to use any of the all-electron                     
relativistic bases without turning on scalar relativity!                        
So, choose RELWFN=LUT-IOTC (or IOTC, DK, RESC) in $CONTRL.                      
5. The core/valence basis sets treat (n-1)s,(n-1)p,ns for                       
s-block elements; (n-1)s,(n-1)p,ns,np for p block elements;                     
(n-1)s,(n-1)p,(n-1)d,ns for d block elements, and the 4s-                       
4f,5s-5d,6s for f block (lanthanides).  This suggests you                       
should change the default number of core orbitals, such as                      
NACORE in $MP2 or NCORE in $CCINP, to correlate the                             
indicated semi-core orbitals (this is not automatic).                           
6. The relativistic sets ("r") are identical to the non-                        
relativistic choices ("-") for atoms H-Ar, where scalar                         
relativity has almost no effect on orbital shapes.                              
7. The relativistic bases were optimized at the 3rd order                       
of the Douglas-Kroll transformation, with a Gaussian nuclei                     
model.  It should be fine to use them with any RESC, DK,                        
IOTC, or LUT-IOTC calculation.                                                  
8. Because they are stored in an external file supplied                         
with GAMESS, these can only be accessed via GBASIS in this                      
group, not by using them in-line in $DATA.                                      
9. The SPK basis sets were extracted from the data base of                      
Segmented Gaussian Basis Sets, maintained by Takeshi Noro,                      
University of Hokkaido, Sapporo, Japan:                                         
    http://setani.sci.hokudai.ac.jp/sapporo/Welcome.do                          
The mapping between the data base names and the keywords                        
used in GAMESS is (for n=D,T,Q):                                                
          data base name               keyword                                  
        Sapporo-nZP                    SPK-nZP                                  
        Sapporo-nZP+diffuse            SPK-AnZP                                 
        Sapporo-DK-nZP                 SPKrnZP                                  
        Sapporo-DK-nZP+diffuse         SPKrAnZP                                 
        Sapporo-nZP-2012               SPK-nZC                                  
        Sapporo-nZP-2012+diffuse       SPK-nZCD                                 
        Sapporo-DK-nZP-2012            SPKrnZC                                  
        Sapporo-DK-nZP-2012+diffuse    SPKrnZCD                                 
                                                                                
                                                                                
                                                                                
     * * * Effective Core Potential (ECP) bases * * *                           
                                                                                
GBASIS = SBKJC- Stevens/Basch/Krauss/Jasien/Cundari                             
                valence basis set, for Li-Rn.  This choice                      
                implies an unscaled -31G basis for H-He.                        
       = HW   - Hay/Wadt valence basis.                                         
                This is a -21 split, available Na-Xe,                           
                except for the transition metals.                               
                This implies a 3-21G basis for H-Ne.                            
                                                                                
                                                                                
        * * * Model Core Potential (MCP) bases * * *                            
                                                                                
Notes: Select PP=MCP in $CONTRL to automatically use the                        
model core potential matching your basis choice below.                          
References for these bases, and other information about                         
MCPs can be found in the REFS.DOC chapter.  Another family                      
covering almost all elements is available in $DATA only.                        
                                                                                
GBASIS = MCP-DZP, MCP-TZP, MCP-QZP -                                            
         a family of double, triple, and quadruple zeta                         
         quality valence basis sets, which are akin to the                      
         correlation consistent sets, in that these include                     
         increasing levels of polarization (and so do not                       
         require "supplements" like NDFUNC or DIFFSP) and                       
         must be used as spherical harmonics (see ISPHER).                      
         Availability:                                                          
         MCP-DZP:          56 elements Z=3-88,                                  
                           except V-Zn, Y-Cd, La, Hf-Hg                         
         MCP-TZP, MCP-QZP: 85 elements Z=3-88, except La                        
         The basis sets for hydrogen atoms will be the                          
         corresponding Dunning's cc-pVNZ (N=D,T,Q).                             
                                                                                
       = MCP-ATZP, MCP-AQZP -                                                   
         MCP-TZP and MCP-QZP core potentials whose                              
         basis sets were augmented with diffuse functions                       
         Availability: same as for MCP-TZP, MCP-QZP                             
                                                                                
       = MCPCDZP, MCPCTZP, MCPCQZP -                                            
         based on MCP-DZP, MCP-TZP, MCP-QZP,                                    
         with core-valence functions provided for the                           
         alkali and alkaline earth atoms Na through Ra.                         
                                                                                
       = MCPACDZP, MCPACTZP, MCPACQZP -                                         
         based on MCPCDZP, MCPCTZP, MCPCQZP,                                    
         with core-valence functions provided for the                           
         alkali and alkaline earth atoms Na through Ra, and                     
         augmented with diffuse functions.                                      
                                                                                
The basis sets were extracted from the data base Segmented                      
Gaussian Basis Sets, maintained by Takeshi Noro, Quantum                        
Chemistry Group, Sapporo, Japan:                                                
    http://setani.sci.hokudai.ac.jp/sapporo/Welcome.do                          
The mapping between the data base names and the names used                      
in GAMESS is                                                                    
         data base name            GAMESS keyword                               
                                                                                
         MCP/NOSeC-V-DZP             MCP-DZP                                    
         MCP/NOSeC-V-TZP             MCP-TZP                                    
         MCP/NOSeC-V-QZP             MCP-QZP                                    
                                                                                
         MCP/NOSeC-V-TZP+diffuse     MCP-ATZP                                   
         MCP/NOSeC-V-QZP+diffuse     MCP-AQZP                                   
                                                                                
         MCP/NOSeC-CV-DZP            MCPCDZP                                    
         MCP/NOSeC-CV-TZP            MCPCTZP                                    
         MCP/NOSeC-CV-QZP            MCPCQZP                                    
                                                                                
         MCP/NOSeC-CV-DZP+diffuse    MCPACDZP                                   
         MCP/NOSeC-CV-TZP+diffuse    MCPACTZP                                   
         MCP/NOSeC-CV-QZP+diffuse    MCPACQZP                                   
                                                                                
GBASIS = IMCP-SR1 and IMCP-SR2 -                                                
         valence basis sets to be used with the improved                        
         MCPs with scalar relativistic effects.                                 
         These are available for transition metals except                       
         La, and the main group elements B-Ne, P-Ar, Ge,                        
         Kr, Sb, Xe, Rn.                                                        
         The 1 and 2 refer to addition of first and second                      
         polarization shells, so again don't use any of the                     
         "supplements" and do use spherical harmonics.                          
       = IMCP-NR1 and IMCP-NR2 -                                                
         closely related valence basis sets, but with                           
         nonrelativistic model core potentials.                                 
                                                                                
GBASIS = ZFK3-DK3, ZFK4-DK3, ZFK5-DK3, or                                       
         ZFK3LDK3, ZFK4LDK3, ZFK5LDK3                                           
These are a family of model core potential basis sets                           
developed by Zeng/Fedorov/Klobukowski, for the p-block                          
elements from 2p to 6p.  The potentials were paramaterized                      
taking into account both DK3 scalar relativistic and DK-SOC                     
effects.  The fundamental basis functions are from the                          
Well-Tempered Basis Sets.  The number after ZFK indicates                       
the augmentation levels, e.g. ZFK3 means the diffuse                            
functions from aug-cc-pVTZ are added, ZFK4 means from aug-                      
cc-pVQZ, etc.  The difference between ZFKn-DK3 and ZFKnLDK3                     
is that the common s and p exponents have been contracted                       
as a single L-shell for the outermost s and p valence                           
shells to save time in the "L" case.  The s-block elements                      
from 1s to 4s have also been put in the library.  For H/He,                     
all-electron aug-cc-pVnZ basis sets are used.  For Li/Be,                       
the relativistically contracted atomic natural orbital all-                     
electron basis sets (ANO-RCC) are used.  For Na/Mg, and                         
K/Ca, unpublished MCP and basis sets based on ANO-RCC are                       
available, although the potentials have not been                                
extensively tested yet.  No d-block elements can be used.                       
                                                                                
                                                                                
        * * * semiempirical basis sets * * *                                    
                                                                                
GBASIS = MNDO - selects MNDO model Hamiltonian                                  
       = AM1  - selects AM1 model Hamiltonian                                   
       = PM3  - selects PM3 model Hamiltonian                                   
       = RM1  - selects RM1 model Hamiltonian                                   
       = DFTB - selects tight binding Hamiltonian                               
                                                                                
Note: The elements for which these exist can be found in                        
the 'further information' section of this manual.  If you                       
pick one of these, all other data in this group is ignored.                     
Semi-empirical runs actually use valence-only Slater type                       
orbitals (STOs), not Gaussian GTOs, but the keyword remains                     
GBASIS.                                                                         
                                                                                
Except for NGAUSS, all other keywords such as NDFUNC, etc.                      
will be ignored for these.  If you add NGAUSS, STO-NG                           
expansions of the valence STO functions in terms of                             
Gaussians will be added to the log file.  Plotting programs                     
such as MacMolPlt can pick up this approximation to the                         
STOs used up from the ouput, in order to draw the orbitals.                     
The default NGAUSS=0 suppresses this output, but values up                      
to 6 may be given to control the accuracy of the STO-NG                         
printing.                                                                       
                                                                                
            --- supplementary functions ---                                     
                                                                                
NDFUNC = number of heavy atom polarization functions to                         
         be used.  These are usually d functions, except                        
         for MINI/MIDI.  The term "heavy" means Na on up                        
         when GBASIS=STO, HW, or N21, and from Li on up                         
         otherwise.  The value may not exceed 3.  The                           
         variable POLAR selects the actual exponents to                         
         be used, see also SPLIT2 and SPLIT3. (default=0)                       
                                                                                
NFFUNC = number of heavy atom f type polarization                               
         functions to be used on Li-Cl.  This may only                          
         be input as 0 or 1.  (default=0)                                       
                                                                                
NPFUNC = number of light atom, p type polarization                              
         functions to be used on H-He.  This may not                            
         exceed 3, see also POLAR.  (default=0)                                 
                                                                                
DIFFSP = flag to add diffuse sp (L) shell to heavy atoms.                       
         Heavy means Li-F, Na-Cl, Ga-Br, In-I, Tl-At.                           
         The default is .FALSE.                                                 
                                                                                
DIFFS  = flag to add diffuse s shell to hydrogens.                              
         The default is .FALSE.                                                 
                                                                                
Warning: if you use diffuse functions, please read QMTTOL                       
in the $CONTRL input group for numerical concerns.                              
                                                                                
POLAR  = exponent of polarization functions                                     
       = COMMON    (default for GBASIS=STO,N21,HW,SBKJC)                        
       = POPN31    (default for GBASIS=N31)                                     
       = POPN311   (default for GBASIS=N311, MC)                                
       = DUNNING   (default for GBASIS=DH, DZV)                                 
       = HUZINAGA  (default for GBASIS=MINI, MIDI)                              
       = HONDO7    (default for GBASIS=TZV)                                     
                                                                                
SPLIT2 = an array of splitting factors used when NDFUNC                         
         or NPFUNC is 2.  Default=2.0,0.5                                       
                                                                                
SPLIT3 = an array of splitting factors used when NDFUNC                         
         or NPFUNC is 3.  Default=4.00,1.00,0.25                                
                                                                                
The splitting factors are from the Pople school, and are                        
probably too far apart.  See for example the Binning and                        
Curtiss paper.  For example, the SPLIT2 value will usually                      
cause an INCREASE over the 1d energy at the HF level for                        
hydrocarbons.                                                                   
                                                                                
The actual exponents used for polarization functions, as                        
well as for diffuse sp or s shells, are described in the                        
'Further References' section of this manual.  This section                      
also describes the sp part of the basis set chosen by                           
GBASIS fully, with all references cited.                                        
                                                                                
Note that GAMESS always punches a full $DATA input group.                       
Thus, if $BASIS does not quite cover the basis you want,                        
you can obtain this full $DATA from EXETYP=CHECK, and then                      
change polarization exponents, add Rydbergs, etc.                               
                                                                                
                                                                                
                       * * *                                                    
                                                                                
This may only be used with COORD=UNIQUE or HINT!                                
                                                                                
BASNAM = an array of names of customized basis set input                        
         groups.  BASNAM should obey the rule of no more                        
         than six characters starting with a letter names,                      
         and must avoid using any GBASIS string.                                
         However, the individual basis inputs can use any                       
         of the GBASIS sets by its standard name.                               
         Basis supplementations such as DIFFS or NDFUNC may                     
         only be given by explicit numerical values.                            
                                                                                
This is best explained by an example where a core potential                     
and valence-only basis set is used on a transition metal,                       
but not its ligands:                                                            
                                                                                
 $contrl scftyp=rohf icharg=+3 mult=4 runtyp=gradient                           
         pp=read ispher=1 $end                                                  
 $system mwords=1 $end                                                          
 $guess  guess=huckel $end                                                      
 $basis  basnam(1)=metal,  ligO,ligO,ligO,ligO,ligO,ligO,                       
                   ligH,ligH,ligH,ligH,ligH,ligH,                               
                   ligH,ligH,ligH,ligH,ligH,ligH $end                           
 $data                                                                          
Cr+3(H2O)6 complex...SBKJC & 6-31G(d) geometry                                  
Th                                                                              
                                                                                
CHROMIUM   24.0    .0000000000  .0   .0000000000                                
OXYGEN      8.0    .0000000000  .0  2.0398916104                                
HYDROGEN    1.0    .7757887450  .0  2.6122732372                                
 $end                                                                           
!       core potential basis for Chromium                                       
 $metal                                                                         
sbkjc                                                                           
                                                                                
 $end                                                                           
!       normal 6-31G(d) for oxygen ligands                                      
 $ligO                                                                          
n31 6                                                                           
d 1 ; 1 0.8 1.0                                                                 
                                                                                
 $end                                                                           
!       unpolarized basis for hydrogens                                         
 $ligH                                                                          
n31 6                                                                           
                                                                                
 $end                                                                           
 $ecp                                                                           
Cr-ecp SBKJC                                                                    
O-ecp none                                                                      
   ...snipped...   there must be 6 O's given here                               
O-ecp none                                                                      
H-ecp none                                                                      
   ...snipped...   there must be 12 H's given here                              
H-ecp none                                                                      
 $end                                                                           
                                                                                
                                                                                
                       * * *                                                    
                                                                                
EXTFIL = a flag to read basis sets from an external file,                       
         defined by EXTBAS, rather than from $DATA.                             
         (default=.false.)                                                      
                                                                                
It may be easier to use BASNAM to create custom basis sets!                     
BASNAM has the bonus that your input file contains all                          
information about the calculation, explicitly.                                  
                                                                                
Except for MCP basis sets, no external file is provided                         
with GAMESS, thus you must create your own.  The GBASIS                         
keyword must give an 8 or less character string, obviously                      
not using any internally stored names.  Every atom must be                      
defined in the external file by a line giving the chemical                      
symbol, and this chosen string. Following this header line,                     
give the basis in free format $DATA style, containing only                      
S, P, D, F, G, and L shells, and terminating each atom by                       
the usual blank line.  The external file may have several                       
families of bases in the same file, identified by different                     
GBASIS strings.                                                                 
                                                                                
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generated on 7/7/2017