Running OPTIM

Any number of optimisation steps can be run with a single call to OPTIM, as specified by the keyword STEPS. The default convergence criteria for eigenvector-following and steepest-descent runs are that the maximum unscaled step size for any coordinate (or eigenvector, depending upon the scaling criterion) is less than $ 10^{-5}$ and the RMS force is also less than $ 10^{-5}$. The number of negative Hessian eigenvalues must also agree with the search type requested. These convergence criteria can be overruled by the CONVERGE keyword, as described in §3.

David Wales 2018-06-23