In polymers and solids, a cutoff distance, in Ångstroms, is needed in order to ensure that
every atom has a correct electric environment. If no cutoff is set, then
equivalent atoms would experience different electric fields. The CUTOFP
distance is set, by default, to 30 Ångstroms. In calculating the potential
due to distant atoms, atoms separated by more than CUTOFP are treated
as if they were at distance CUTOFP.
MOZYME calculations run faster when smaller
values of CUTOFP are used A suitable value for n.nn is
somewhere between 10.0 and 15.0. This will give a
large increase in speed. But first, run a test calculation to verify that the
results don't change much.
When CUTOFP is less than the default, the number of two-electron
integrals is reduced. This can allow larger systems to be run.