Abstract
A new method of calculating molecular crystal structures is proposed and tested. The repulsive portion of the nonbonded potential energy is fitted by a quadratic equation to yield a sum-of-squares description of the repulsive lattice energy. Minimization of this sum by full-matrix least squares yields good fits to the observed crystal structures of several hydrocarbons. The convergence properties of the method are markedly superior to those of the steepest-descent method, and calculation times are greatly decreased.