$CPHF group     (relevant for analytic RUNTYP=HESSIAN)
 
    This group controls the solution of the response
equations, also known as coupled Hartree-Fock (CPHF).
 
POLAR = a flag to request computation of the static
        polarizability, alpha.  Because this property
        needs 3 additional response vectors, beyond those
        needed for the hessian, the default is to skip the
        property.  (default = .FALSE.)
 
CPHF   = nature of integrals driving the formation of the
         response equation.  The defaults are intelligent,
         so this is meant mostly for experts/debugging.
       = AO    forms response equations from AO integrals,
               which usually takes less memory, and is more
               parallel.  This is the default for RHF, UHF,
               ROHF, R-DFT, or U-DFT.  AO-driven mode is
               not available for any other cases.
       = MO    forms response equations from transformed
               MO integrals.  This is the default for GVB
               or MCSCF.  This is available forRHF or ROHF.
       = AODDI forms response equations from AO integrals,
               using distributed memory (see MEMDDI).  This
               does AO integrals about 2x more than AO,
               but spreads the CPHF memory requirement out
               across multiple nodes.  Coded only for RHF.
 
SOLVER = linear equation solver choice.  This is primarily
         a debugging option.  For RHF analytic Hessians,
         choose from CONJG (default), DIIS, ONDISK, not all
         of which will work for all CPHF= choices.
         For imaginary frequency dependent polarizability
         responses (MAKEFP jobs), choose GMRES (default),
         biconjugate gradient stabilized BCGST, DODIIS, or
         an explicit solver GAUSS.  Most response equations
         have only one solver programmed, and thus ignore
         this keyword.
 
NWORD  = controls memory usage for this step.  The default
         uses all available memory.  (default=0)