How do I find information about atomic charges used in MacroModel calculations?
Usually, partial atomic charges used in an energetic computation are obtained from information stored in the force-field (.fld) file (or from the BMFF co-process, for OPLS-2001 or MMFF). However, MacroModel will use the charges that appear in the structure input file if the CHGF command appears in the command file. After an energetic computation is complete, the charges—as determined by the force field in use—appear in the output structure file. When the force-field file is used as the charge source, there are three types of information that affect the partial charges: bond dipoles, formal charges, and explicit substructure charges. Bond Dipoles Bond dipoles are stored in the stretch part of the force field. The following example is from the AMBER* force field: 1 CT – H1 1.0900 331.0000 -0.6597 N400 0000 ^^^^^^^ The highlighted number is the bond dipole (D, in debye) that is applied between types CT and H1. Partial charges Q and -Q (in units of e) would be assigned to the atoms CT and
