To run a DRF calculation two block keys, DRF and EXTERNALS, are required. The DRF key controls the general options and the EXTERNALS key provides the atomic data for the MM atoms. The DRF key should not be used in combination with: COSMO, QM/MM, geometry optimization, frequency calculation or point charges.
A DRF calculation are invoked by the following block key DRF:
DRF
{NORESP}
{NOPOL}
{NOCHAR}
{LOCALFIELD}
{EFIELD ex ey ez &}
{AFAC a}
end
NORESP
DRF is ignored in RESPONSE and EXCITATION
NOPOL
The many-body operator is ignored (no induced dipoles)
NOCHAR
The Coulomb operator is ignored (no charges)
LOCALFIELD
Local Fields are included
EFIELD
Homogeneous external electric field is included. ex value of field in x-direction, ey value of field in y-direction, and ez value of field in z-direction. A continuation symbol, &, is required. The units are atomic units.
