Three body forces in DL_POLY_2 are only permissible with cubic
, orthorhombic and
parallelepiped periodic
boundaries. Use of other boundary conditions results in this error.
Action:
If nonperiodic boundaries are required, the only option is to use a
very large simulation cell, with the required system at the centre
surrounded by a vacuum. This is not very efficient however and use of
a realistic periodic system is the best option.