On the calculation of ab initio quantum molecular similarities for large systems: Fitting the electron density

AbstractA set of procedures for rapid calculation of quantum molecular similarities from ab initio wave functions is discussed. In all cases a density fitting is carried out to eliminate the need of calculating costly four‐centered integrals. It is proved that this methodology can be applied to large systems to reproduce exact quantum molecular similarity measures at an extremely low computational cost. © 1994 by John Wiley & Sons, Inc.