$SCRF

$SCRF group (optional)

The presence of this group in the input turns on the use of the Kirkwood-Onsager spherical cavity model for the study of solvent effects. The method is implemented for RHF, UHF, ROHF, GVB and MCSCF wavefunctions and gradients, and so can be used with any RUNTYP involving the gradient. The method is not implemented for MP2, CI, any of the semiempirical models, or for analytic hessians.

DIELEC
= the dielectric constant, 80 is often used for H2O

RADIUS
= the spherical cavity radius, in Angstroms

G
= the proportionality constant relating the solute molecule's dipole to the strength of the reaction field. Since G can be calculated from DIELEC and RADIUS, do not give G if they were given.

Some references on this subject are

J.G.Kirkwood J.Chem.Phys. 2, 351 (1934)
L.Onsager J.Am.Chem.Soc. 58, 1486 (1936)
O.Tapia, O.Goscinski Mol.Phys. 29, 1653 (1975)
M.M.Karelson, A.R.Katritzky, M.C.Zerner Int.J.Quantum Chem., Symp. 20, 521-527 (1986)
K.V.Mikkelsen, H.Aagren, H.J.Aa.Jensen, T.Helgaker J.Chem.Phys. 89, 3086-3095 (1988)
M.W.Wong, M.J.Frisch, K.B.Wiberg J.Am.Chem.Soc. 113, 4776-4782 (1991)
M.Szafran, M.M.Karelson, A.R.Katritzky, J.Koput, M.C.Zerner J.Comput.Chem. 14, 371-377 (1993)
M.Karelson, T.Tamm, M.C.Zerner J.Phys.Chem. 97, 11901-11907 (1993)

It is useful to think about Figures 1 and 2 of the Szafran reference when you are picking DIELEC and RADIUS values! GAMESS implements Zerner's Method A, as described in this paper. The total solute energy includes the Born term, if the solute is an ion.

It is useful to think about Table VI of the Mikkelsen paper, lest you think a solute consists only of a charge and a dipole moment.

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