qmmm long range electrostatic cutoff
Getting rc2 in qmmm.py to work (courtesy of E. Ö. Jónsson).
Nothing has changed to the original strategy of the cutoff. The switching function value is just based on the center of mass of each MM molecule, and applied to all MM atoms of that molecule. Seems to give smooth transitions:
I more or less accidentally snuck in a tip4p test as well, into this MR. I couldn't find any in the latest master.
This version of qmmm.py will not work unless GPAW is also updated according to this MR