Selecting search parameters for GMIN

There are a few general tips for selecting parameters for geometry optimisation.

1. The number of STEPS should be long enough to at least see one conformational change without restarting.

2. The step size STEP should be roughly 2/3 of an interaction distance for atomic clusters. Longer distances maybe required for the system.

3. The number of My-LBFGS minisation steps MAXIT should be large enough so 99% of the steps converge. This promotes more efficient sampling.

4. The final quenches should be ordered with respect to their energies. If they are not, it means that lower energy structure have been found upon tight convergence and the SLOPPYCONV needs to be tightened. Also if the same minimum is being found with the tight convergence it suggests SLOPPYCONV is not differentiating between minima well, and therefore should be tightened as well.

5. The TEMPERATURE should be high enough to over come barrier heights., but not so large that all barriers are overcome thereby causing the rescaling of the move step to result in very large steps which may take a long time to converge. This is system dependent and requires testing to ensure efficient sampling.