$DANDC group  (optional, relevant if SCFTYP=RHF or UHF)                         
    This group controls the divide-and-conquer (DC) SCF                         
calculations, in which the total 1-electron density matrix                      
is obtained as sum of subsystem density matrices.  In this                      
calculation, the total system is partitioned into several                       
disjoint subsystems (central regions).  A subsystem density                     
matrix is expanded by bases in the central region and its                       
neighboring environmental region (buffer).                                      
   The present implementation allows energy and analytic                        
nuclear gradients, for HF, DFT, and semi-empirical runs,                        
for SCFTYP=RHF or UHF only.  The discrete EFP and various                       
continuum solvation models are available.  DC correlation                       
energies are also available for either MP2 and CC, see                          
$DCCORR, without nuclear gradients.  Dynamic and static                         
polarizabilities (but no hyperpolarizabilities) based on                        
DC-HF are available by specifying RUNTYP=TDHF (not TDHFX).                      
    The initial guess is given by a density matrix, not                         
orbitals.  The only available options are GUESS=HUCKEL,                         
HCORE, HUCSUB, DMREAD, and MOREAD (the latter means                             
orbitals for the entire system).                                                
    For a review paper on Divide-and-Conquer in GAMESS:                         
        M.Kobayashi, H.Nakai                                                    
          in Linear-Scaling Techniques in Computational                         
          Chemistry and Physics: Methods and Applications                       
          (Springer), Chap. 5 (2011)                                            
    For more information on the DC-SCF method, see                              
        W.Yang, T.-S.Lee                                                        
          J.Chem.Phys. 103, 5674-5678(1995)                                     
        T.Akama, M.Kobayashi, H.Nakai                                           
          J.Comput.Chem. 28, 2003-2012(2007)                                    
        T.Akama, A.Fujii, M.Kobayashi, H.Nakai                                  
          Mol.Phys. 105, 2799-2804(2007)                                        
        T.Akama, M.Kobayashi, H.Nakai                                           
          Int.J.Quant.Chem. 109, 2706-2713(2009)                                
        M.Kobayashi, T.Yoshikawa, H.Nakai                                       
          Chem.Phys.Lett. 500, 172-177(2010) [open-shell]                       
        M.Kobayashi, T.Kunisada, T.Akama, D.Sakura, H.Nakai                     
          J.Chem.Phys. 134, 034105/1-11(2011) [gradient]                        
    For more information on DC-MP2 and DC-CC, see                               
        M.Kobayashi, Y.Imamura, H.Nakai                                         
          J.Chem.Phys. 127, 074103/1-7(2007)                                    
        M.Kobayashi, H.Nakai                                                    
          J.Chem.Phys. 129, 044103/1-9(2008)                                    
        M.Kobayashi, H.Nakai                                                    
          J.Chem.Phys. 131, 114108/1-9(2009)                                    
        M.Kobayashi, H.Nakai                                                    
          Int.J.Quant.Chem. 109, 2227-2237(2009)                                
    For more information on DC-TDHF polarizability, see                         
        T.Touma, M.Kobayashi, H.Nakai                                           
          Chem.Phys.Lett. 485, 247-252(2010)                                    
    Of course, the trick to methods that divide up a large                      
problem into small ones is to control the errors that                           
result.  A simple way to set up a DC-MP2 calculation is                         
with atomic partitions:                                                         
 $contrl scftyp=rhf mplevl=2 runtyp=energy $end                                 
 $system mwords=25 $end                                                         
 $scf    dirscf=.true. $end                                                     
 $dandc  dcflg=.true. subtyp=atom bufrad=8.0 $end                               
 $dccorr dodccr=.true. rbufcr=5.0 $end                                          
 $guess  guess=hucsub $end  (if DC-SCF is used)                                 
This leads to as many subsystems as there are atoms, with                       
the buffer region around the central atom being defined by                      
a radius.  This input recognizes that exchange effects in                       
Hartree-Fock are longer range than correlation, and thus                        
uses dual level radii.  It may be reasonable to simply do a                     
conventional and thus fully accurate SCF computation by                         
DCFLG=.FALSE., obtaining only the MP2 correlation energy by                     
the divide and conquer method.  Faster run times may result                     
from other partitionings, such as manually dividing a                           
protein into subsystems containing a single amino acid.                         
DCFLG =        flag to activate DC-SCF calculation.                             
  Note:  If you want to treat only the correlated MP2/CC                        
         procedure in the DC manner, after a standard HF                        
         calculation, this option may be set to .FALSE.                         
SUBTYP =        chooses a method to construct disjoint                          
                subsystems (central region).                                    
       = ATOM   individual atom is 1 subsystem.                                 
                (default if NSUBS=0 or not given)                               
       = MANUAL manually selects using NSUBS and LBSUBS                         
                keywords. (default if NSUBS>=1)                                 
       = CARD   reads from card. $SUBSCF is used for SCF                        
                and $SUBCOR for MP2/CC calculation.                             
       = AUTO   constructs subsystems automatically by                          
                dividing total system by cubic grid.                            
                Grid size can be set by SUBLNG.                                 
       = AUTBND considers bond strength after AUTO.                             
NSUBS  = number of subsystems when SUBTYP=MANUAL.                               
LBSUBS = an array assigning atoms to subsystems.                                
         The style is the same as INDAT keyword in $FMO.                        
         Two styles are supported (the choice is made based                     
         on LBSUBS(1): if it is nonzero, choice (a) is                          
         taken, otherwise LBSUBS(1) is ignored and choice                       
         (b) is taken):                                                         
         a) LBSUBS(i)=m assigns atom i is to subsystem m.                       
            LBSUBS(i) must be given for each atom.                              
         b) the style is                                                        
            a1 a2 ... ak 0                                                      
            b1 b2 ... bm 0                                                      
            Elements a1...ak are assigned to subsystem 1,                       
            then b1...bm are assigned to subsystem 2,etc.                       
            An element is one of the following:                                 
                I    or   I -J                                                  
            where I means atom I, and a pair I,-J means                         
            the range of atoms I-J.  There must be no space                     
            after the "-"!                                                      
         LBSUBS(1)=1,1,1,2,2,1 is equivalent to                                 
         LBSUBS(1)=0, 1,-3,6,0, 4,5,0                                           
         Both assign atoms 1,2,3 and 6 to subsystem 1,                          
         and 4,5 to subsystem 2.                                                
SUBLNG = grid length of cube used in SUBTYP=AUTO or AUTBND.                     
         This value should be in the unit given by UNITS                        
         keyword in $CONTRL.  (default=2.0 Angstroms).                          
BUFTYP = chooses a method to construct buffer region.                           
       = RADIUS selects atoms included in spheres centered                      
                at atoms in the central region (default).                       
                The radius is given by BUFRAD keyword for                       
                DC-SCF and by the RBUFCR keyword in $DCCORR                     
                for DC-MP2/CC.                                                  
       = RADSUB selects subsystems containing one or more                       
                atom(s) which is included in spheres                            
                centered at atoms in the central region.                        
                This selection can avoid cutting bonds                          
                within each subsystem.                                          
       = CARD   reads from $SUBSCF or $SUBCOR card.                             
                Only available when SUBTYP=CARD.                                
BUFRAD = buffer radius in DC-SCF calculation. This value                        
         should be in the units given by UNITS keyword in                       
         $CONTRL (default=5.0 Angstroms).                                       
FRBETA = inverse temperature parameter of Fermi function                        
         used in DC-SCF procedure in a.u. (default=200.0)                       
         Reducing this value may improve SCF convergence                        
         but may obtain worse total energy.                                     
MXITDC = maximum number of iteration cycles for determining                     
         Fermi level (default=100). Usually, you need not                       
         care about this keyword.                                               
FTOL   =   Fermi function cutoff factor (default=15.0).                         
       = p The value of Fermi function less than 10**(-p)                       
           is considered as 0. The value greater than                           
           [1 - 10**(-p)] is considered as 1.                                   
NDCPRT =    DC print-out option which is the sum of                             
            followings (default=0).                                             
       = +1 not used (reserved).                                                
       = +2 prints density matrix ($DM section) on punch.                       
       = +4 prints energy corresponding to each subsystem.                      
            Gives correct energy only in HF calculation.                        
       = +8 prints orbitals in each subsystem.                                  
IORBD  =   selects molecular orbital in total system whose                      
           electron density is to be computed.                                  
           Print format is given in $ELDENS.                                    
       = -1, -2, ...  correspond to HOMO, HOMO-1, ...                           
       = 1, 2, ...    correspond to LUMO, LUMO+1, ...                           
       = 0            no calculation (default).                                 
In the DC-SCF procedure, the available SCF acceleration                         
techniques are DIIS, DAMP, EXTRAP as well as DC-DIIS and                        
VFON which are specific to the DC-SCF.  In DC-SCF                               
calculation, only DIIS is used by default.  DC-DIIS                             
(DIIDCF=.TRUE.) is not normally needed for convergence.                         
The following keywords control (DC-)DIIS convergence:                           
DIITYP =        selects the error vector used in the                            
                standard DIIS extrapolation                                     
       = FDS    Pulay's modified DIIS (e=FDS-SDF). Although                     
                this type of error vector behaves well in                       
                standard SCF, it may not for DC-SCF.                            
       = DELTAF Pulay's original DIIS (e[i]=F[i]-F[i-1]),                       
                or so-called Anderson mixing (default).                         
DIIQTR = .TRUE.  uses orthogonal basis (in entire system)                       
                 for DIIS extrapolation.  Normally, this                        
                 does not make sense in DC-SCF run.                             
         .FALSE. uses atomic basis function for DIIS                            
                 extrapolation (default).                                       
EXTDII = energy error threshold in absolute value for                           
         exiting DIIS (default=0.0).                                            
PEXDII = percentage threshold of energy error change for                        
         exiting DIIS (default=1.0). PEXDII is                                  
         preferential to EXTDII.                                                
DIIDCF = a flag to activate DC-DIIS interpolation                               
ETHRDC = energy error threshold for initiating DC-DIIS.                         
         Increasing ETHRDC forces DC-DIIS on sooner                             
         (default = 1.D-4 if DIIDCF=.TRUE.).                                    
The following keywords control the convergence acceleration                     
based on the varying fractional occupation number (VFON).                       
The final electronic temperature is given by FRBETA.                            
FONTYP =        selects the variation pattern of electronic                     
                temperature (beta) in SCF iteration                             
       = DIIER  logarithmic variation with respect to DIIS                      
       = NONE   no variation (default).                                         
BETINI = initial beta value in a.u.                                             
         (default = FRBETA/4 for FONTYP=DIIER).                                 
FONSTA = threshold to start variation of beta                                   
         (default=1.0 for FONTYP=DIIER).                                        
FONEND = threshold to stop variation of beta                                    
         (default=1.D-4 for FONTYP=DIIER).                                      
When FONTYP=DIIER, the beta value used in the iteration                         
(of which the DIIS error is DIISer) is the following:                           
     beta = BETINI [for DIISER>FONSTA]                                          
          = FRBETA [for DIISER<=FONEND]                                         
          = FRBETA + C_FON * Log(DIISer/FONEND) [otherwise]                     
where (C_FON = (BETINI-FRBETA) / Log(FONSTA/FONEND)                             
Option for the type of nuclear gradient:                                        
NDCGRD =   selects the DC-SCF gradient implementation                           
        = 0 use a formula proposed by Yang and Lee in 1995                      
        = 1 use a formula proposed by Kobayashi et al. in                       
          2011 (default)                                                        
Next are options for printing density of states (DOS).                          
DOSITV = Interval between plot points in Hartree. The                           
         default is zero,meaning no DOS print-out. If                           
         you print out DOS, DOSITV=0.05 may be sufficient.                      
DOSRGL = Left end of the plot range in Hartree.                                 
DOSRGR = Right end of the plot range in Hartree.                                
BDOS   = Inverse temperature parameter (beta) for                               
         distributing states. This value should not be                          
         given because it is set to be equivalent to FRBETA                     
         in $DANDC by default.                                                  

generated on 7/7/2017