Is it possible to calculate interaction energies with MacroModel?
Yes, the mechanism to perform atom set interaction energy calculations uses the ASET opcode. When ASET is included, multiple atom sets can be defined, and a subsequent ELST command in the instruction file instructs MacroModel to report the interaction energies among and between the indicated atom sets. ASET is described in the MacroModel Reference Manual, and there is an example in the MacroModel User Manual. Unfortunately, there is not currently an interface to this feature in Maestro. Additionally, the eMBrAcE automated mechanism, in its interaction mode, utilizes the ASET mechanism to calculate the eMBrAcE energies. Thus if you are interested in the interaction energy between pre-positioned ligands and a receptor, then eMBrAcE interaction mode is a valuable implementation of the ASET mechanism.
