FEP benchmarking set

Benchmarking set for alchemical relative binding free energy calculations. The data includes structures for 10 congeneric ligand-pairs bound to their receptor. The benchmarking set is challenging since 6 out of the 10 ligand modifications occur in buried pockets, where the solvent cannot equilibrate well with bulk in short timescales. Furthermore, input file for the Desmond LigandFEP module are contained.