23.3 CPHF for gradients, expectation values and polarizabilities

The accuracy and other parameters of the CPHF calculations necessary to compute gradients and response properties can be modified using the CPHF directive:

CPHF, [THRMIN=thrmin], [THRMAX=thrmax], [MAXIT=maxit], [SHIFT=shift], [SAVE=record], [START=record], [DIIS=idiis], [DISM=idism]

THRMIN

CPHF convergence threshold (default 1.d-6). THRESH and ACCU are aliases for this.

THRMAX

initial CPHF convergence threshold in geometry optimizations. Once the geometry is converged to a certain accuarcy (depending on OPTCONV), the threshold is stepwise reduced to THRMIN.
The default is THRMAX=min(1.d-6,THRMIN*100); Values larger than 1.d-6 are ignored.

MAXIT

Maxmimum number of iterations (default 50).

SHIFT

Level shift for CPHF (default 0.1).

DIIS

First macroiteration in which DIIS is used (default 1)

DISM

First microiteration in which DIIS is used (default 1; in microiterations the core contribution is frozen).

SAVE

Record on which the CPHF solution can be saved for later restarts. The solution is saved automatically in geometry optimizations and frequency calculations.

START

Record from which initial guess is read. A starting guess is read automatically in geometry optimizations and frequency calculations.