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 the Int=Grid option. The argument to this option may be a grid keyword (Fine, UltraFine, and so on) or a specific grid.
The default grid is FineGrid. In this case, the default grid for the CPHF is Coarse. When UltraFine is used for the integrals, then SG1 is used for the CPHF; if SG1 is selected as the integration grid, the Coarse grid is again used for the CPHF. When a specific grid is specified to the Integral=Grid option, then that grid is also used for the CPHF. Finally, be aware that SG1 is used in CPHF as the default integration grid for a few DFT jobs including Polar=OptRot, Freq=Anharmonic and Freq=NNROA (and Coarse is used in the CPHF in those cases).
See the discussion of Integral=Grid for 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 of cm (cm-1) and nm (wavelength). This option is relevant for Freq and Polar jobs. It is the default for Freq=ROA.
Static
Automatically include the static perturbations when doing dynamic ones. This is the default except for Polar=OptRot and Freq=ROA. NoStatic says not to perform static perturbations in combination with dynamic via RdFreq.
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 by MaxInv is exceeded. Otherwise, the default is NoRecursiveDIIS, which says to invert the reduced A-matrix.
MaxInv=N
Specifies the largest reduced space for in-core inversion during simultaneous solution (up to dimension N). 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). NonEqSolv is 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 with RdFreq (see below).
Separate
Use a separate expansion space for each variable in the CPHF (the opposite of Simultaneous). This is the default and only choice when multiple frequencies are specified with RdFreq.
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 is N=9 for CPHF=Separate and N=10 for CPHF=Simultaneous (the default).
Canonical
Canonical CPHF, the default.
MOD
Use MOD orbital derivatives for SAC-CI gradients (which uses configuration selection).
Last update: 2 August 2013