The calculation of the stress tensor in DL_POLY_2 requires
additional code that must be included at compile time through the use
of the STRESS keyword. If this is not done, and DL_POLY_2 is
later required to calculate the stress tensor, this error will
result.
Action:
The program must be recompiled with the STRESS keyword activated. This
will ensure all the relevant code is in place. See section 3.2.1.