Multicenter point charge model for high‐quality molecular electrostatic potentials from AM1 calculations

The natural atomic orbital/point charge (NAO‐PC) model based upon the AM1 wave function has been developed to calculate molecular electrostatic potentials (MEPs). Up to nine point charges (including the core charge) are used to represent heavy atoms. The positions and magnitudes of the eight charges that represent the atomic electron cloud are calculated from the natural atomic orbitals (NAOs) and their occupations. Each hybrid NAO is represented by two point charges situated at the centroid of each lobe. The positions of the centroids and the magnitudes of the charges were obtained by numerical integration of the Slater‐type hybrids and the results used to set up polynomials and look‐up tables that replace the integration step in the actual MEP calculation. The MEPs calculated using this method are found to be in better agreement with those obtained using RHF/6‐31G* than those obtained from the AM1 wave function using Coulson charges or with MOPAC‐ESP. The MEP calculations are extremely fast and have, for instance, been incorporated into an interactive graphics package. © 1993 John Wiley & Sons, Inc.

[1]  J. Gasteiger,et al.  ITERATIVE PARTIAL EQUALIZATION OF ORBITAL ELECTRONEGATIVITY – A RAPID ACCESS TO ATOMIC CHARGES , 1980 .

[2]  György G. Ferenczy,et al.  Semiempirical AM1 electrostatic potentials and AM1 electrostatic potential derived charges: A comparison with ab initio values , 1989 .

[3]  Bernard Pullman,et al.  Intermolecular interactions, from diatomics to biopolymers , 1978 .

[4]  Eamonn F. Healy,et al.  Development and use of quantum mechanical molecular models. 76. AM1: a new general purpose quantum mechanical molecular model , 1985 .

[5]  Frank Weinhold,et al.  Natural hybrid orbitals , 1980 .

[6]  M. Marsili.  Computation of Volumes and Surface Areas of Organic Compounds , 1988 .

[7]  P. Kollman,et al.  Atomic charges derived from semiempirical methods , 1990 .

[8]  Ramon Carbo,et al.  How similar is a molecule to another? An electron density measure of similarity between two molecular structures , 1980 .

[9]  Laura Bonati,et al.  Molecular electrostatic potential of substituted aromatic compounds: Factors affecting the differences between Ab Initio and semiempirical results , 1992 .

[10]  M. Dewar,et al.  Ground States of Molecules. 38. The MNDO Method. Approximations and Parameters , 1977 .

[11]  Anthony J. Stone,et al.  Distributed multipole analysis, or how to describe a molecular charge distribution , 1981 .

[12]  Donald E. Williams,et al.  Representation of the molecular electrostatic potential by a net atomic charge model , 1981 .

[13]  Christopher A. Hunter,et al.  The nature of .pi.-.pi. interactions , 1990 .

[14]  Mark S. Gordon,et al.  Self‐consistent molecular orbital methods. XXIII. A polarization‐type basis set for second‐row elements , 1982 .

[15]  J. Tomasi,et al.  Electrostatic interaction of a solute with a continuum. A direct utilizaion of AB initio molecular potentials for the prevision of solvent effects , 1981 .

[16]  J. Stewart.  Optimization of parameters for semiempirical methods I. Method , 1989 .

[17]  Eugene S. Kryachko,et al.  Theory of molecular interactions , 1986 .

[18]  G H Loew,et al.  Quantum chemical studies of morphine-like opiate narcotics. Effect of N-substituent variations. , 1975, Journal of medicinal chemistry.

[19]  P. Kollman,et al.  An approach to computing electrostatic charges for molecules , 1984 .

[20]  Catherine Burt,et al.  The application of molecular similarity calculations , 1990 .