Default implementation of P/A. We return a data structure that contains all changes required from this run, the enerDif or energy difference between the known and the predicted structure, and a structural difference score. Furthermore, some errors are being reported in errors.

The energy difference can be (i) in that case, a wrongly predicted structure has better (lower) energy than the known one. (ii) It can be zero, then we have either found a co-optimal structural or the correct structure. (iii) In some cases, it can be positive, this is a formal error, but will not abort the program. (The calling program may opt to abort on (not . null $ errors).

The structural difference is [0..1] with 0 for structurally identical predictions and known structures and otherwise growing toward 1 for bad predictions where nothing is correct.

In case that the known structure has a score epsilon better than the predicted, we have an error condition, as this should never be the case.

Return a lot of information from each P/A call. We do not return the new Params anymore, only a list of changes. This allows us to do some things. If the implementation of Params is switched, we can update in place; or we can perform calculations in parallel.