$PCMGRD group                               (optional)
 
    This group controls the PCM gradient computations.  It
is of a technical nature, and is seldom given.
 
IPCDER = selects different methods for PCM gradients
         1  use Ux(q) approximation (C-PCM and IEF-PCM),
            or use charge-derivative method (D-PCM).
            This is the default for D-PCM.
         2  Variable-Tessera-Number Approximation.
            Implemented only for C-PCM and IEF-PCM, and
            the default for GEPOL-AS tesselation.
         3  The same as 2, but for FIXPVE tessellation.
The program will pick the correct default for IPCDER!
 
note: If ICAV = 1 or IDISP = 1 in $PCM, the derivatives
      of the cavitation energy or dispersion-repulsion,
      respectively, will automatically be calculated.
      You must be using the following input:
        $PCM ICAV=1 IDISP=1 $END
        $DISREP ICLAV=1 $END
 
IFAST  = Controls the PCM calculations for RUNTYP=OPTIMIZE.
         0  update PCM charges at each SCF cycle at every
            geometry (default)
         1  update PCM charges at each SCF cycle for the
            initial geometry.
            For the subsequent geometries, calculate PCM
            charges at the first SCF cycle and use the PCM
            charges for the following SCF cycles; after
            the density change falls below DENTOL, update
            the PCM charges one time (to save CPU time).