Message 120: error - invalid determinant in matrix inversion

DL_POLY_2 occasionally needs to calculate matrix inverses (usually the inverse of the matrix of cell vectors, which is of size 3 $\times$ 3). For safety's sake a check on the determinant is made, to prevent inadvertent use of a singular matrix.

Action:
Locate the incorrect matrix and fix it - e.g. are cell vectors correct?