178 COMPUTER HARDWARE, SOFTWARE
this force fi eld with new functional terms and new parameters to represent the
latest science from the CHARMM community. Two HyperChem versions are
available for Macintosh. HyperChem for Mac B.1 is supported for the Mac
mini, iMac, iBook, PowerBook, and PowerMac, but not the G5 machine with
its 64 - bit processor. HyperChem Mac B.2 runs on the new Intel Macintosh
machines.
MOMEC97, available at http://www.uni - heidelberg.de/institute/fak12/AC/
comba/ , is a program for strain energy minimization, designed to be used in
conjugation with HyperChem in a Windows environment. MOMEC97 is a
program for strain energy minimization. The program was developed by the
Peter Comba and Trevor Hambley for modeling transition metal compounds,
especially transition metal coordination compounds, but may be used in many
areas of inorganic and organic chemistry. MOMEC97, used in conjunction with
HyperChemTM , carries out optimization of geometries in MOMEC, then model
building and visualization in HyperChem TM. The program contains an exten-
sive force fi eld for transition metal and rare earth compounds, along with a
module for the refi nement of Jahn – Teller distortions in hexacoordinate coor-
dination compounds (see Sections 1.5.2 and 1.6 ). The Jahn – Teller module ’ s
approach is based on a fi rst order harmonic model that minimizes the sum of
steric strain and electronic stabilization. The strain energy calculation uses the
MOMECEnergy module with the metal - donor distances following a Jahn –
Teller mode — that is, elongation of the metal – ligand distances on the z - axis
by 2 d and compression of the in - plane metal – ligand bonds by d. The electronic
term depends on the ideal metal - donor distance, the type of ligand ( σ or π
bonding) and the ligand fi eld strength. Several applications of the MOMEC
program by researchers can be found in reference 42.
Schrodinger, Inc. at http://www.schrodinger.com/ offers a number of model-
ing and calculation packages. Jaguar TM , running on Unix workstations, is a
high - performance ab initio quantum mechanical application for gas and solu-
tion phase simulations with particular strength in metal - containing systems.
The program uses methods including Hartree – Fock theory, generalized valence
bond theory (GVB), density functional theory (DFT), and second - order local
M ö ller – Plesset perturbation theory (LMP2). The Jaguar TM program can model
important solvent effects by applying a self - consistent reaction fi eld (SCRF).
Jaguar TM computes molecular properties including NMR, IR, p Ka , partial
charges, multipole moments, polarizabilities, molecular orbitals, electron
density, and electrostatic potentials. Jaguar accepts a wide variety of input
formats. MacroModel TM , Schrodinger ’ s molecular modeling program, also
requiring workstation architecture, has a large user base in the scientifi c com-
munity. The program features molecular graphics, molecular mechanics, and a
large selection of force fi elds and advanced methods for conformational analy-
sis, molecular dynamics, and free - energy calculations. Use of a wide array of
force fi elds — MM2, MM3, AMBER, AMBER94, MMFF, OPLS, OPLS - AA —
is possible. The program handles conformational analyses of entire proteins as
well as small molecules. The Maestro TM graphical user interface (GUI), also a