Patent ID: 7765070

Claim:
A method of constructing an ellipsoidal Gaussian representation of a molecular field of a molecule for use when searching a database of molecular structures, the method comprising: choosing a number of ellipsoidal Gaussian functions to represent the molecular field, wherein the molecular field is stored in a database, and wherein each ellipsoidal Gaussian function has a prefactor, three width factors, coordinates of its center, and three mutually orthogonal unit vectors that define the directions of its principal axes; centering each ellipsoidal Gaussian function at a randomly chosen starting position and with a randomly chosen starting orientation within the molecular field; forcing each ellipsoidal Gaussian function to initially adopt a spherical shape; constructing the ellipsoidal Gaussian representation from the values of the coordinates of the center, the orientations of the principal axes, the magnitudes of the width factors and the size of the prefactor that give a maximal overlap between the molecular field and the ellipsoidal Gaussian functions; and storing the ellipsoidal Gaussian representation of the molecular field in the database, thereby providing an index for searching the database, wherein at least the choosing, the centering, the forcing and the constructing are carried out on a computer, and wherein the database is stored on the computer.