Multiresolution quantum chemistry in multiwavelet bases: Hartree-Fock exchange

An efficient numerical algorithm to evaluate Hartree-Fock (HF) exchange in the multiresolution SCF method to solve the HF method was discussed. It was found that the algorithm employed fast integral convolution with the Poission kernel in the nonstandard form, screening the sparse multiwavelet representation to compute results of the integral operator. It was observed that the localized molecular orbital were used to attain near linear scalings. Analysis of the small water clusters demonstrates a total cost to compute the HF exchange potential for all n _ncc occupied MOs scaling as O(n _occ ^1.5).