$DFT group                 (relevant if DFTTYP is chosen)                       
                         (relevant if SCFTYP=RHF,UHF,ROHF)                      
    Note that if DFTTYP=NONE, an ab initio calculation will                     
be performed, rather than density functional theory.                            
     This group permits the use of various one electron                         
(usually empirical) operators instead of the true many                          
electron Hamiltonian.  Two programs are provided, METHOD=                       
GRID or GRIDFREE.  The programs have different functionals                      
available, and so the keyword DFTTYP (which is entered in                       
$CONTRL) and other associated inputs are documented                             
separately below.  Every functional that has the same name                      
in both lists is an identical functional, but each METHOD                       
has a few functionals that are missing in the other.                            
    The grid free implementation is based on the use of the                     
resolution of the identity to simplify integrals so that                        
they may be analytically evaluated, without using grid                          
quadratures.  The grid free DFT computations in their                           
present form have various numerical errors, primarily in                        
the gradient vectors.  Please do not use the grid-free DFT                      
program without reading the discussion in the 'Further                          
References' section regarding the gradient accuracy.                            
    The grid based DFT uses a typical grid quadrature to                        
compute integrals over the rather complicated functionals,                      
using two possible angular grid types.                                          
    Achieving a self-consistent field with DFT is rather                        
more difficult than for normal HF, so DIIS is the default                       
    Both DFT programs will run in parallel. See the two                         
lists below for possible functionals in the two programs.                       
    See also the $TDDFT input group for excited states.                         
METHOD = selects grid based DFT or grid free DFT.                               
       = GRID     Grid based DFT (default)                                      
       = GRIDFREE Grid free DFT                                                 
DFTTYP is given in $CONTRL, not here in $DFT!  Possible                         
values for the grid-based program are listed first,                             
          ----- options for METHOD=GRID -----                                   
DFTTYP = NONE     means ab initio computation (default)                         
Many choices are given below, perhaps the most sensible are                     
               local DFT: SVWN                                                  
            pure DFT GGA: BLYP, PW91, B97-D, PBE/PBEsol                         
          hybrid DFT GGA: B3LYP, X3LYP, PBE0                                    
       pure DFT meta-GGA: revTPSS                                               
     hybrid DFT meta-GGA: TPSSh, M06                                            
but of course, everyone has their own favorite!                                 
              pure exchange functionals:                                        
       = SLATER   Slater exchange                                               
       = BECKE    Becke 1988 exchange                                           
       = GILL     Gill 1996 exchange                                            
       = OPTX     Handy-Cohen exchange                                          
       = PW91X    Perdew-Wang 1991 exchange                                     
       = PBEX     Perdew-Burke-Ernzerhof exchange                               
These will be used with no correlation functional at all.                       
              pure correlation functionals:                                     
       = VWN      Vosko-Wilk-Nusair correlation, using                          
                  their electron gas formula 5 (aka VWN5)                       
       = VWN3     Vosko-Wilk-Nusair correlation, using                          
                  their electron gas formula 3                                  
       = VWN1RPA  Vosko-Wilke-Nusair correlation, using                         
                  their e- gas formula 1, with RPA params.                      
       = PZ81     Perdew-Zener 1981 correlation                                 
       = P86      Perdew 1986 correlation                                       
       = LYP      Lee-Yang-Parr correlation                                     
       = PW91C    Perdew-Wang 1991 correlation                                  
       = PBEC     Perdew-Burke-Ernzerhof correlation                            
       = OP       One-parameter Progressive correlation                         
These will be used with 100% HF exchange, if chosen.                            
              combinations (partial list):                                      
       = SVWN     SLATER exchange + VWN5 correlation                            
                  Called LDA/LSDA in physics for RHF/UHF.                       
       = SVWN1RPA Slater exchange + VWN1RPA correlation                         
       = BLYP     BECKE exchange + LYP correlation                              
       = BOP      BECKE exchange + OP correlation                               
       = BP86     BECKE exchange + P86 correlation                              
       = GVWN     GILL exchange + VWN5 correlation                              
       = GPW91    GILL exchange + PW91 correlation                              
       = PBEVWN   PBE exchange + VWN5 correlation                               
       = PBEOP    PBE exchange + OP correlation                                 
       = OLYP     OPTX exchange + LYP correlation                               
       = PW91     means PW91 exchange + PW91 correlation                        
       = PBE      means PBE exchange + PBE correlation                          
There's a nearly infinite set of pairings (well, 6*9), so                       
we show only enough to give you the idea.  In other words,                      
pairs are formed by abbreviating the exchange functionals                       
    SLATER=S, BECKE=B, GILL=G, OPTX=O, PW91X=PW91, PBEX=PBE                     
and matching them with any correlation functional, of which                     
only two are abbreviated when used in combinations,                             
    PW91C==>PW91, PBEC==>PBE                                                    
The pairings shown above only scratch the surface, but                          
clearly, many possibilities, such as PW91PBE, are nonsense!                     
             pure DFT GGA functionals:                                          
       = EDF1     empirical density functional #1, which is                     
                  a modified BLYP from Adamson/Gill/Pople.                      
       = PW91     Perdew/Wang 1991                                              
       = PBE      Perdew/Burke/Ernzerhof 1996                                   
       = revPBE   PBE as revised by Zhang/Yang                                  
       = RPBE     PBE as revised by Hammer/Hansen/Norskov                       
       = PBEsol   PBE as revised by Perdew et al for solids                     
       = HCTH93   Hamprecht/Cohen/Tozer/Handy's 1998 mod                        
                  to B97, omitting HF exchange, fitting to                      
                  93 atoms and molecules                                        
       = HCTH120  later fit to 120 systems                                      
       = HCTH147  later fit to 147 systems                                      
       = HCTH407  later fit to 407 systems (best)                               
       = SOGGA    PBE revised by Zhao/Truhlar for solids                        
       = MOHLYP   metal optimized OPTX, half LYP                                
       = B97-D    Grimme's modified B97, with dispersion                        
                  correction (this forces DC=.TRUE.)                            
       = SOGGA11  optimized with broad applicability for                        
                  chemistry, by Peverati/Zhao/Truhlar                           
             hybrid GGA functionals:                                            
       = BHHLYP   HF and BECKE exchange + LYP correlation                       
       = B3PW91   Becke's 3 parameter exchange hybrid,                          
                  with PW91 correlation functional                              
       = B3LYP    this is a hybrid method combining five                        
                  functionals: Becke + Slater + HF exchange                     
                  (B3), with LYP + VWN5 correlation.                            
                  B3LYPV5 is a synonym for B3LYP.                               
       = B3LYPV1R use VWN1RPA in place of VWN5, matches the                     
                  e- gas formula chosen by some programs.                       
       = B3LYPV3  use VWN3 in place of B3LYP's VWN5                             
       = B3P86    B3-type exchange, P86 correlation, using                      
                  VWN3 as the LDA part of the correlation.                      
                  B3P86V3 is a synonym for B3P86.                               
       = B3P86V1R use VWN1RPA in place of VWN3                                  
       = B3P86V5  use VWN5 in place of VWN3                                     
       = B97      Becke's 1997 hybrid functional                                
       = B97-1    Hamprecht/Cohen/Tozer/Handy's 1998                            
                  reparameterization of B97                                     
       = B97-2    Wilson/Bradley/Tozer's 2001 mod to B97                        
       = B97-3    Keal/Tozer's 2005 mod to B97                                  
       = B97-K    Boese/Martin's 2004 mod for kinetics                          
       = B98      Schmider/Becke's 1998 mode to B97,                            
                  using their best "2c" parameters.                             
       = PBE0     a hybrid made from PBE                                        
       = X3LYP    HF+Slater+Becke88+PW91 exchange,                              
                  and LYP+VWN1RPA correlation.                                  
       = SOGGA11X a hybrid based on SOGGA11,                                    
                  with 40.15% HF exchange.                                      
Each includes some Hartree-Fock exchange, and also may use                      
a linear combination of many DFT parts.                                         
           range separated functionals:                                         
These are also known as "long-range corrected functionals".                     
LC-BVWN, LC-BOP, LC-BLYP, or LC-BPBE are available by                           
selecting BVWN, BOP, BLYP, or BPBE and also setting the                         
flag LC=.TRUE. (see LC and also MU below).  Others are                          
selected by their specific name, without using LC:                              
       = CAMB3LYP coulomb attenuated B3LYP                                      
       = wB97     omega separated form of B97                                   
       = wB97X    wB97 with short-range HF exchange                             
       = wB97X-D  dispersion corrected wB97X                                    
M11 is also range-separated, but is listed below with the                       
other meta-GGAs.                                                                
              "double hybrid" GGA:                                              
       = B2PLYP   mixes BLYP, HF exchange, and MP2!                             
                  See related inputs CHF and CMP2 below.                        
          "double hybrid" and "range separated":                                
       = wB97X-2  intended for use with GBASIS=CCT,CCQ,CC5                      
       = wB97X-2L intended for use with GBASIS=N311                             
                  NGAUSS=6 NDFUNC=3 NFFUNC=1 NPFUNC=3                           
                  DIFFSP=.T. DIFFS=.T.                                          
Note: there are no analytic gradients for "double hybrids".                     
Note: the B2PLYP family uses the conventional MP2 energy                        
and may be used for closed shell or spin-unrestricted open                      
shell cases.  The wB97X-2 family uses the SCS-MP2 energy,                       
and thus is limited to closed shell cases at present.                           
              meta-GGA functionals:                                             
These are not hybridized with HF exchange, unless that is                       
explicitly stated below.                                                        
       = VS98     Voorhis/Scuseria, 1998                                        
       = PKZB     Perdew/Kurth/Zupan/Blaha, 1999                                
       = tHCTH    Boese/Handy's 2002 metaGGA akin to HCTH                       
       = tHCTHhyb tHCTH's hybrid with 15% HF exchange                           
       = BMK      Boese/Martin's 2004 parameterization of                       
                  tHCTHhyb for kinetics                                         
       = TPSS     Tao/Perdew/Staroverov/Scuseria, 2003                          
       = TPSSh    TPSS hybrid with 10% HF exchange                              
       = TPSSm    TPSS with modified parameter, 2007                            
       = revTPSS  revised TPSS, 2009                                            
       = dlDF     a reparameterized M05-2X, reproducing                         
                  interaction energies which have had all                       
                  dispersion removed.  This MUST be used                        
                  with a special -D correction to recover                       
                  dispersion.  See 'Further References'.                        
       = M05      Minnesota exchange-correlation, 2005                          
                  a hybrid with 28% HF exchange.                                
       = M05-2X   M05, with doubled HF exchange, to 56%                         
       = M06      Minnesota exchange-correlation, 2006                          
                  a hybrid with 27% HF exchange.                                
       = M06-L    M06, with 0% HF exchange (L=local)                            
       = M06-2X   M06, with doubled HF exchange, to 54%                         
       = M06-HF   M06 correlation, using 100% HF exchange                       
       = M08-HX   M08 with 'high HF exchange'                                   
       = M08-SO   M08 with parameters that enforce the                          
                  correct second order gradient expansion.                      
       = M11      M11 range-separated hybrid                                    
       = M11-L    M11 local (0% HF exchange) with                               
                  dual-range exchange                                           
When the M06 family was created, Truhlar recommended M06                        
for the general situation, but see his "concluding remarks"                     
in the M06 reference about which functional is best for                         
what kind of test data set.  The most recent M11 family is                      
probably a better choice, and two functionals fit all the                       
needs of the older M05/M06/M08 families.                                        
An extensive bibliography for all functionals can be                            
found in the 'Further References' section of this manual.                       
Note that only a subset of these functionals can be used                        
for TD-DFT energy or gradients.  These subsets are listed                       
in the $TDDFT input group.                                                      
* * * dispersion corrections * * *                                              
Many exchange-correlation functionals fail to compute                           
intra- and inter-molecular dispersion interactions                              
accurately.  Two possible correction schemes are provided                       
below.  The first uses empirically chosen C6 and C8                             
coefficients, while the latter obtains these from the                           
molecular DFT densities.  At most, only one of the LRDFLG                       
or DC options below may be chosen.                                              
DC     = a flag to turn on Grimme's empirical dispersion                        
         correction, involving scaled R**(-6) terms.                            
         N.B.  This empiricism may also be added to plain                       
         Hartree-Fock, by choosing DFTTYP=NONE with DC=.T.                      
         Three different versions exist, see IDCVER.                            
         (default=.FALSE., except if DFTTYP=B97-D, wB97X-D)                     
IDCVER = 1 means 1st 2004 implementation.                                       
       = 2 means 2nd 2006 implementation DFT-D2,                                
           default for B97-D, wB97X-D.                                          
       = 3 means 3rd 2010 implementation DFT-D3.                                
           Default if DC is chosen and IDCVER isn't given.                      
       = 4 means modified 3rd implementation DFT-D3(BJ).                        
           (-4 is used for DFT-D3(BJ) for HF-3c).                               
         Setting IDCVER will force DC=.TRUE.                                    
GCP     = a flag for the geometric counterpoise scheme                          
          correction in HF-3c.                                                  
SRB     = a flag for short-range basis set incompleteness                       
          (SRB) correction in HF-3c.                                            
DCCHG  = a flag to use Chai-Head-Gordon damping function                        
         instead of Grimme's 2006 function. Pertinent only                      
         for the DFT-D2 method.  Forces DC=.TRUE.                               
         (default=.FALSE. except for wB97X-D)                                   
DCABC  = a flag to turn on the computation of the E(3) non-                     
         additive energy term. Pertinent only for DFT-D3,                       
         it forces DC=.TRUE.  (default=.FALSE.)                                 
    The following parameters govern Grimme's semiempirical                      
dispersion term. They are basis set and functional                              
dependent, so they exist for only a few DFTTYP. Default                         
values are automatically selected and printed out in the                        
output file for many common density functionals.                                
    The following keywords are for entering non-standard                        
values. For DFT-D2 values, see also:                                            
      R.Peverati and K.K.Baldridge                                              
      J.Chem.Theory Comput. 4, 2030-2048 (2008).                                
For DFT-D3 values, and a detailed explanation of each                           
parameter, see:                                                                 
      S. Grimme, J. Antony, S. Ehrlich and H. Krieg,                            
      J.Chem.Phys. 132, 154104/1-19(2010)                                       
and for DFT-D3(BJ):                                                             
      S. Grimme, S. Ehrlich and L. Goerigk,                                     
      J.Comput.Chem. 32, 1456-1465 (2011)                                       
DCALP  = alpha parameter in the DFT-D damping function                          
         (same as alpha6 in Grimme's DFT-D3 notation).                          
         Note also that alpha8 and alpha10 in DFT-D3 have                       
         constrained values of:                                                 
         alpha8 = alpha6 + 2, alpha10 = alpha8 + 2.                             
         Default=14.0 for DFT-D3                                                
                =20.0 for DFT-D2                                                
                =23.0 for DFT-D1                                                
                =6.00 for DCCHG=.TRUE.                                          
DCSR   = sR exponential parameter to scale the van der                          
         Waals radii (same as sR,6 in Grimme's DFT-D3                           
         notation). Note also that sR,8 in DFT-D3 have a                        
         fixed value of 1.0.                                                    
         Optimized values are automatically selected for                        
         some of the more common functionals, otherwise,                        
         the default is 1.00 for DFT-D3, 1.10 for DFT-D2,                       
         and 1.22 for DFT-D1.                                                   
DCS6   = s6 linear parameter for scaling the C6 term.                           
         Optimized values are automatically selected for                        
         some of the more common functionals, otherwise,                        
         the default is 1.00.                                                   
DCS8   = s8 linear parameter for scaling the C8 term of                         
         DFT-D3. Pertinent only for DFT-D3.                                     
         Optimized values are automatically selected for                        
         some of the more common functionals, otherwise,                        
         the default is 1.00.                                                   
DCA1   = a1 parameter appearing in the -D3(BJ) dispersion                       
         model. Optimized values are automatically                              
         selected for a set of known functionals,                               
         otherwise the default is 0.50.                                         
DCA2   = a2 parameter appearing in the -D3(BJ) dispersion                       
         model. Optimized values are automatically                              
         selected for a set of known functionals,                               
         otherwise the default is 4.00.                                         
The old keywords DCPAR and DCEXP were replaced by DCS6 and                      
DCSR in 2010.  Similarly, DCOLD has morphed into IDCVER.                        
                          - - -                                                 
The Local Response Dispersion (LRD) correction includes                         
atomic pair-wise -C6/R**6, -C8/R**8, and -C10/R**10 terms,                      
whose coefficients are computed from the molecular system's                     
electron density and its nuclear gradient.  The nuclear                         
gradient assumes the dispersion coefficients do not vary                        
with geometry, which causes only a very small error in the                      
gradient.  Optionally, 3 and 4 center terms may be added,                       
at the 1/R**6 level; in this case, nuclear gradients may                        
not be computed at all.                                                         
Since the three numerical parameters are presently known                        
only for the long-range exchange corrected BOP functional,                      
calculations may specify simply DFTTYP=LCBOPLRD.  The                           
"LCBOPLRD" functional will automatically select the                             
     DFTTYP=BOP   LC=.TRUE. MU=0.47                                             
     LRDFLG=.TRUE. LAMBDA=0.232 KAPPA=0.600 RZERO=3.22                          
leaving only the choice for MLTINT up to you.                                   
References for LRD are                                                          
   T.Sato, H.Nakai J.Chem.Phys. 131, 224104/1-12(2009)                          
   T.Sato, H.Nakai J.Chem.Phys. 133, 194101/1-9(2010)                           
LRDFLG = flag choosing the Local Response Dispersion (LRD)                      
         C6, C8, and C10 corrections.  Default=.FALSE.                          
MLTINT = flag to add the 3 and 4 center 6th order terms,                        
         the default=.FALSE.  Note that nuclear gradients                       
         are not available if these multi-center terms                          
         are requested.                                                         
Three numerical parameters may be input.  The defaults                          
shown are optimized for the BOP functional with the LC                          
correction for long-range exchange.                                             
LAMBDA = parameter adjusting the density gradient                               
         correction for the atomic and atomic pair                              
         polarizabilities.  (default=0.232)                                     
KAPPA  = parameter in the damping function (default=0.600)                      
RZERO  = parameter in the damping function (default=3.22)                       
It may be interesting to see a breakdown of the total                           
dispersion correction, using these keywords:                                    
PRPOL  = print out atomic effective polarizabilities                            
PRCOEF = N  (default N=0)                                                       
         print out dispersion coefficient to N-th order.                        
PRPAIR = print out atomic pair dispersion energies                              
              * * * range separation * * *                                      
LC     = flag to turn on the long range correction (LC),                        
         which smoothly replaces the DFT exchange by the                        
         HF exchange at long inter-electron distances.                          
         This option can be used only with the Becke                            
         exchange functional (Becke) and a few correlation                      
         functionals: DFTTYP=BVWN, BOP, BLYP, BPBE only.                        
         For example, B3LYP has a fixed admixture of HF                         
         exchange, so it cannot work with the LC option.                        
         See H.Iikura, T.Tsuneda, T.Yanai, and K.Hirao,                         
         J.Chem.Phys. 115, 3540 (2001).                                         
MU     = A parameter for the long range correction scheme.                      
         Increasing MU increases the HF exchange used,                          
         very small MU produces the DFT limit.                                  
Other range-separated options exist, invoked by naming the                      
functional, such as DFTTYP=CAMB3LYP (see the DFTTYP keyword                     
for a full list).                                                               
    * * * B2x-PLYP double hybrid functionals * * *                              
B2xPLYP Double Hybrid functionals have the general formula:                     
    Exc = (1-cHF) * ExGGA + cHF * ExHF                                          
       + (1-cMP2) * EcGGA + cMP2 * E(2)                                         
The next keywords allow the choice of cHF and cMP2. Both                        
values must be between 0 and 1 (0-100%).                                        
CHF    = amount of HF exchange. (default=0.53)                                  
CMP2   = amount of MP2. (default=0.27)                                          
Some other common double hybrid functionals are available                       
simply by choosing DFTTYP=B2PLYP, and changing the CHF and                      
CMP2 parameters. Popular parametrizations are:                                  
                             CHF       CMP2                                     
     B2-PLYP (default)   |   0.53  |   0.27   |                                 
     B2K-PLYP            |   0.72  |   0.42   |                                 
     B2T-PLYP            |   0.60  |   0.31   |                                 
     B2GP-PLYP           |   0.65  |   0.36   |                                 
                 * * * Grid Input * * *                                         
Only one of the three grid types may be chosen for the run.                     
The default (if no selection is made) is the Lebedev grid.                      
In order to duplicate results obtained prior to April 2008,                     
select the polar coordinate grid NRAD=96 NTHE=12 NPHI=24.                       
Energies can be compared if and only if the identical grid                      
type and density is used, analogous to needing to compare                       
with the identical basis set expansions.  See REFS.DOC for                      
more information on grids.  See similar inputs in $TDDFT.                       
Lebedev grid:                                                                   
NRAD   = number of radial points in the Euler-MacLaurin                         
         quadrature. (default=96)                                               
NLEB   = number of angular points in the Lebedev grids.                         
         (default=302).  Possible values are 86, 110, 146,                      
         170, 194, 302, 350, 434, 590, 770, 974, 1202,                          
         1454, 1730, 2030...                                                    
Meta-GGA functionals require a tighter grid to achieve the                      
same accuracy. For this reason a tighter default grid of                        
NRAD=99 and NLEB=590 is chosen by default with all meta-GGA                     
The default for NLEB means that nuclear gradients will be                       
accurate to about the default OPTTOL=0.00010 (see $STATPT),                     
590 approaches OPTTOL=0.00001, and 1202 is "army grade".                        
The next two specify radial/angular in a single keyword:                        
SG1    = a flag to select the "standard grid 1", which has                      
         24 radial points, and various pruned Lebedev                           
         grids, from 194 down to 6.  (default=.FALSE.                           
         This grid is very fast, but produces gradients                         
         whose accuracy reaches only OPTTOL=0.00050.                            
         This grid should be VERY USEFUL for the early                          
         steps of a geometry optimization.                                      
JANS   = two unpublished grids due to Curtis Janssen,                           
         implemented here differently than in MPQC:                             
       = 1 uses 95 radial points for all atoms, and prunes                      
           from a Lebedev grid whose largest size is 434,                       
           thus using about 15,000 grid points/atom.                            
       = 2 uses 155 radial points for all atoms, and prunes                     
           from a Lebedev grid whose largest size is 974,                       
           thus using about 71,000 grid points/atom.                            
           This is a very accurate grid, e.g. "army grade".                     
       The information for pruning exists only for H-Ar,                        
       so heavier elements will use the large radial/                           
       Lebedev grid without any pruning.                                        
polar coordinate grid:                                                          
NRAD   = number of radial points in the Euler-MacLaurin                         
         quadrature. (96 is reasonable)                                         
NTHE   = number of angle theta grids in Gauss-Legendre                          
         quadrature (polar coordinates). (12 is reasonable)                     
NPHI   = number of angle phi grids in Gauss-Legendre                            
         quadrature.  NPHI should be double NTHE so points                      
         are spherically distributed. (24 is reasonable)                        
The number of angular points will be NTHE*NPHI.  The values                     
shown give a gradient accuracy near the default OPTTOL of                       
0.00010, while NTHE=24 NPHI=48 approaches OPTTOL=0.00001,                       
and "army grade" is NTHE=36 NPHI=72.                                            
              * * * Grid Switching * * *                                        
At the first geometry of the run, pure HF iterations will                       
be performed, since convergence of DFT is greatly improved                      
by starting with the HF density matrix.  After DFT engages,                     
most runs (at all geometries, except for PCM or numerical                       
Hessians) will use a coarser grid during the early DFT                          
iterations, before reaching some initial convergence.                           
After that, the full grid will be used.  Together, these                        
switchings can save considerable CPU time.                                      
SWOFF =  turn off DFT, to perform pure SCF iterations,                          
         until the density matrix convergence falls below                       
         this threshold.  This option is independent of                         
         SWITCH and can be used with or without it. It is                       
         reasonable to pick SWOFF > SWITCH > CONV in $SCF.                      
         SWOFF pertains only to the first geometry that the                     
         run computes, and is automatically disabled if you                     
         choose GUESS=MOREAD to provide initial orbitals.                       
         The default is 5.0E-3.                                                 
SWITCH = when the change in the density matrix between                          
         iterations falls below this threshhold, switch                         
         to the desired full grid (default=3.0E-4)                              
         This keyword is ignored if the SG1 grid is used.                       
NRAD0  = same as NRAD, but defines initial coarse grid.                         
         default = smaller of 24 and NRAD/4                                     
NLEB0  = same as NLEB, but defines initial coarse grid.                         
         default = 110                                                          
NTHE0  = same as NTHE, but defines initial coarse grid.                         
         default = smaller of 8, NTHE/3                                         
NPHI0  = same as NPHI, but defines initial coarse grid.                         
         default = smaller of 16, NPHI/3                                        
technical parameters:                                                           
THRESH = threshold for ignoring small contributions to the                      
         Fock matrix.  The default is designed to produce                       
         no significant energy loss, even when the grid is                      
         as good as "army grade".  If for some reason you                       
         want to turn all threshhold tests off, of course                       
         requiring more CPU, enter 1.0e-15.                                     
         default: 1.0e-4/Natoms/NRAD/NTHE/NPHI                                  
GTHRE  = threshold applied to gradients, similar to THRESH.                     
         < 1 assign this value to all thresholds                                
         = 1 use the default thresholds (default).                              
         > 1 divide default thresholds by this value.                           
         If you wish to increase accuracy, set GTHRE=10.                        
         The default introduces an error of roughly 1e-7                        
         (a.u./bohr) in the gradient.                                           
The keyword $DFTTYP is given in $CONTRL, and may have these                     
values if the grid-free program is chosen:                                      
        ----- options for METHOD=GRIDFREE -----                                 
DFTTYP = NONE     means ab initio computation (default)                         
                     exchange functionals:                                      
       = XALPHA   X-Alpha exchange (alpha=0.7)                                  
       = SLATER   Slater exchange (alpha=2/3)                                   
       = BECKE    Becke's 1988 exchange                                         
       = DEPRISTO Depristo/Kress exchange                                       
       = CAMA     Handy et al's mods to Becke exchange                          
       = HALF     50-50 mix of Becke and HF exchange                            
                     correlation functionals:                                   
       = VWN      Vosko/Wilke/Nusair correlation, formula 5                     
       = PWLOC    Perdew/Wang local correlation                                 
       = LYP      Lee/Yang/Parr correlation                                     
                     exchange/correlation functionals:                          
       = BVWN     Becke exchange + VWN5 correlation                             
       = BLYP     Becke exchange + LYP correlation                              
       = BPWLOC   Becke exchange + Perdew/Wang correlation                      
       = B3LYP    hybrid HF/Becke/LYP using VWN formula 5                       
       = CAMB     CAMA exchange + Cambridge correlation                         
       = XVWN     Xalpha exchange + VWN5 correlation                            
       = XPWLOC   Xalpha exchange + Perdew/Wang correlation                     
       = SVWN     Slater exchange + VWN5 correlation                            
       = SPWLOC   Slater exchange + PWLOC correlation                           
       = WIGNER   Wigner exchange + correlation                                 
       = WS       Wigner scaled exchange + correlation                          
       = WIGEXP   Wigner exponential exchange + correlation                     
AUXFUN = AUX0  uses no auxiliary basis set for resolution                       
               of the identity, limiting accuracy.                              
       = AUX3  uses the 3rd generation of RI basis sets,                        
               These are available for the elements H to                        
               Ar, but have been carefully considered for                       
               H-Ne only.  (DEFAULT)                                            
THREE  = a flag to use a resolution of the identity to                          
         turn four center overlap integrals into three                          
         center integrals.  This can be used only if                            
         no auxiliary basis is employed. (default=.FALSE.)                      

generated on 7/7/2017