This type specifies Girifalco's C intermolecular potential
with periodic boundary conditions (minimum image convention). If keyword
PRESSURE is specified in odata
then a constant pressure type optimisation is performed,
as described for SC, above. However, in this case the lattice constant optimisation is
achieved by eigenvector-following. As for SC, the cutoff is changed in proportion to
the box size. Four extra parameters must be specified in the odata file using the
as for SC. Subroutines used: latmin, c60p.