Program pdm97, Least-Squares Fitting of the Molecular Electrostatic Potential
With Net Atomic Charges and/or Multipoles

The following is a brief description of this program.

Molecules interact with each other via their electric potential.
pdm97 finds optimized net atomic charges and other site multipole
representations of the molecular electric potential based on a variety
of models. The program is easy to use, flexible and powerful. Results
are normally obtained in a single iteration and a complete error treatment
is made which includes estimated standard deviation and correlation of
variables. The program is written in Fortran 77 and runs very efficiently
on any computer with F77 capability. Source code is provided.

Program pdm97 has a unique combination of features:

• excellent agreement with quantum mechanical multipole moments
• general sites, e.g. united atoms, not necessarily at atomic locations
• each site may have any combination of monopole, dipole, or quadrupole
• allowance for molecular ionization
• bond dipole model is supported
• restricted (along the bond direction) bond dipole model is supported
• provision for site dipole vectors in sp2 or sp3 directions
• selected fixed atomic charges
• selected groups of atoms with fixed charge
• atomic charge equalities or symmetry relations
• rotational invariance of site charges
• provision for hyperbolic-restricted charge magnitudes
• provision for optional foreshortening of X-H bonds
• comparison with Mulliken charges and Mulliken electric potential
• direct input from Gaussian-92 or G-94 output file
• generalized input from other quantum mechanics programs
• geodesic, Connolly, and cubic grids for MEP are available
• provision for custom generation of MEP grid points
• error analysis with standard deviations and correlations
• on-line program manual
• comprehensive examples are provided

For further information contact Dr. Donald E. Williams, Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, USA.

Tel:(502)852-5975
Fax:(502)852-8149
E-mail: dew01@xray5.chem.louisville.edu

----------------------------------------------------------------------- Ordering information

Program package consisting of manuals, Fortran-77 source files, and example test files, single computer license....................$2,000

Discount price for academic users, campus license....................$395

Normal shipment is via ftp; please provide an account protected with a temporary password to receive the program.

Make check (in US$) payable to the University of Louisville and mail
Dr. Donald E. Williams
Department of Chemistry
University of Louisville
Louisville, KY 40292
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