add mmCIF writer and maybe others
We currently only have parseMMCIF but not writeCIF or writeMMCIF. We do have parseSTAR and writeSTAR, but that may not be specific enough.
It could be good to provide a connection to some other library such as mdanalysis, mdtraj, chemfiles or gemmi so we can use their writers for mmCIF files and other formats.
MDTraj doesn't have one but there is a also PDBx/mmCIF writer in BioPython that we could use (see https://github.com/mdtraj/mdtraj/issues/652).
Has this been implemented yet? And has it been implemented to write pqr data to cif? Also, if not I would like to vote for gemmi.
Thanks Danny. Someone else suggested GEMMI to me too
This is now solved in #1816