Christian Selzer

Implement atomic masses

3

I implemented the atomic masses. This helps to assimilate tad-mctc (https://github.com/tad-mctc/tad-mctc/tree/main) and mctc-lib. the code is covered by tests. The masses are taken from the xtb repository (commit 7618f60). build...

This should address issue #889 . I made the iter_needed variable which tracks the number of needed iterations needed to complete the geometry optimization an optional variable, as this feature...