MacroModel Reference Manual - ISP

Chapter 1: Capabilities and New Features1.4 Program CapacityMacroModel uses dynamic memory allocation. For most computations, the size of the systemthat can be studied is limited only by the resources of the computer on which the simulation isperformed. Some compiled-in limits remain, and a few are described below:• MAXFV—The maximum number of atoms that can be used in certain second-derivativeprocedures. Opcodes that are affected by this limit are documented in the opcode descriptions.For this version of MacroModel MAXFV is 1100.• The maximum number of comparison atoms that can be specified is 20,000. In addition,the total number of fixed and frozen atoms cannot exceed 20,000. Structural restraints canbe applied to sets of atoms, but the limit is 20,000 each of stretches, bends, and torsions.The maximum number of structures that can be saved in a conformational search or multipleminimization is under user control. See:• Arg1 of MCMM, LMCS, LMC2, and SPMC• Arg2 of MULT• Arg5 of LOOP1.5 Miscellaneous• The SPAT command allows the user to instruct MacroModel how to proceed when itencounters certain atom types.• The GEOM command allows the user to obtain geometric information about the moleculefrom the MacroModel command file.• Many properties are now recorded in Maestro-formatted output structure files. Theseproperties are displayed in Maestro’s project table.1.6 Citing MacroModel in PublicationsThe use of this product should be acknowledged in publications as:MacroModel, version 9.7, Schrödinger, LLC, New York, NY, 2009.MacroModel 9.7 Reference Manual 9