matrix [class i] [class j] [potential name] [parameters] [class i] [class j] [potential name] [parameters]where the potential names and parameters are specified below. The interaction matrix is assumed to be symmetric, so if is specified, should not be specified.

*SANDBOX* will compute certain values that pertain to individual sites only if those sites interact with certain potentials. For example, if a site interacts with some other site according to a dipole interaction, then must be computed for both sites. If the row (or column) corresponding to a site's interaction contains only empty or isotropic interactions, however, is not computed.

David Wales 2017-11-23