This keyword selects the algorithm used for solving the CPHF equations[McWeeny60,McWeeny62,Stevens63,Gerratt68,Dodds77,Dodds77a,Wolinski80,Osamura81,Osamura82,Pulay83,Dykstra84].
Grid=grid
Specify the integration grid for the CPHF portion of the calculation. The syntax is the same as for theInt=Gridoption. The argument to this option may be a grid keyword (Fine,UltraFine, and so on) or a specific grid.
The default grid isFineGrid. In this case, the default grid for the CPHF isCoarse. WhenUltraFineis used for the integrals, thenSG1is used for the CPHF; ifSG1is selected as the integration grid, theCoarsegrid is again used for the CPHF. When a specific grid is specified to theIntegral=Gridoption, then that grid is also used for the CPHF. Finally, be aware thatSG1is used in CPHF as the default integration grid for a few DFT jobs includingPolar=OptRot,Freq=AnharmonicandFreq=NNROA(andCoarseis used in the CPHF in those cases).
See the discussion ofIntegral=Gridfor full details on grid specification.
RdFreq
Perform frequency-dependent (dynamic) CPHF, reading in the incident light frequency for the electromagnetic field perturbation. The desired frequency must be provided in the input stream. The default units for this value are Hartrees. Other units may be specified by including a suffix, one ofcm(cm-1) andnm(wavelength). This option is relevant forFreqandPolarjobs. It is the default forFreq=ROA.
Static
Automatically include the static perturbations when doing dynamic ones. This is the default except forPolar=OptRotandFreq=ROA.NoStaticsays not to perform static perturbations in combination with dynamic viaRdFreq.
RecursiveDIIS
Solve reduced equations using recursive DIIS. This is the default when the number of right-hand sides is at least twice the dimension of the reduced matrix and the dimension of the reduced matrix is large (occurs only for ONIOM(MO:MM) using electronic embedding), or the limit set byMaxInvis exceeded. Otherwise, the default isNoRecursiveDIIS, which says to invert the reduced A-matrix.
MaxInv=N
Specifies the largest reduced space for in-core inversion during simultaneous solution (up to dimensionN). Larger reduced problems are solved by a second level of DIIS. The default is 5000.
EqSolv
Use equilibrium solvation. This is the default for static perturbations (i.e., zero frequency fields and nuclear displacements).NonEqSolvis the default for dynamic (non-zero frequency) perturbations.
Simultaneous
Use one expansion space for all variables. This is faster than using separate spaces, but is slightly less accurate. This is the default except when multiple frequencies are specified withRdFreq(see below).
Separate
Use a separate expansion space for each variable in the CPHF (the opposite ofSimultaneous). This is the default and only choice when multiple frequencies are specified withRdFreq.
AO
Solve CPHF in the atomic orbital basis[Stevens63,Osamura81,Osamura82,Pulay83]. This is the default.
MO
Solve in the molecular orbital basis.
Conver=N
Set the CPHF convergence criterion to 10-N. The default isN=9 forCPHF=SeparateandN=10 forCPHF=Simultaneous(the default).
Canonical
Canonical CPHF, the default.
MOD
Use MOD orbital derivatives forSAC-CIgradients (which uses configuration selection).
Last update: 2 August 2013