>We just had a chance to read this most interesting discussion. We would agree with Ian that jiggling or SA refinement may not be needed if refinement can in fact be run to convergence. However, this will be difficult to achieve for large structures, especially when only moderate to low resolution data are available.
I find this interesting—is refinement convergence related to resolution? Is this because the structure-landscape is not sufficiently defined to find the real global minimum? I wonder what would happen if Ian Tickle’s test were done on many structures, and results examined as a function of resolution? Predictions? I guess generally there are more ways to fit fewer data points than many, but then perhaps refinement convergence would be more dependent on parameter:observation ratios than resolution per se, although quantities are closely related all things being equal. JPK
