**** RMS GRADIENT IS TOO LARGE TO ALLOW...

In AMPAC 8, the translational and rotational “vibrations” are
computed analytically and the force constant matrix is projected from the subspace of the
genuine vibrations. This corrects the harmonic force field by removing the residual first
order components present because the system is not exactly a stationary point. The geometry
must be very near a stationary point so that third and higher order components do not corrupt
the quadratic force field. Before a
FORCE calculation can be
performed the gradient norm must very low. If the gradient norm is too large,
the calculation will be halted. This condition may be overridden by use of
the keyword LET. See Chapter 4, *Computational Procedures* for a
discussion
of stationary points and the implications of incompletely optimized geometries.

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