$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. (default=.FALSE.) 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 "-"! Example: 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 (default=.FALSE.). 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 error. = 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. (default=-2.0) DOSRGR = Right end of the plot range in Hartree. (default=+2.0) 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