There are two other methods programmed in Cadpac. The optimisation keyword may be modified as follows,
OPTIMISE MINIMUM method
where method is one of the following character strings ,
This causes use of an augmented hessian technique, and
which causes use of Pulay's DIIS method as applied to geometry searches.
Generally speaking we have found little difference in the performance
of all these methods, except that in cases where the initial guess at the
geometry is rather poor, then the augmented hessian technique seems to
converge more rapidly in the initial stages - its overall performance is
however no better than BFGS.
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