THE EFFICIENT TRANSFORMATION OF (M0-VERTICAL-BAR-N0) TO (AB-VERTICAL-BAR-CD) 2-ELECTRON REPULSION INTEGRALS

A new method is presented for transforming (m0/n0) integrals to (ab/cd ) integrals efficiently. A key feature of the new approach is the opti mization of the total number of memory operations (mops) rather than f loating-point operations (flops). Solutions to the inherent tree-searc h problem were obtained which are radically different than those follo wing when flops are taken as the cost function. These involve new, mul ti-unit angular momentum transfer relations which belong to a general family having the familiar one-unit transfer relation of Head-Gordon a nd Pople as its simplest member. CPU timings demonstrate the new metho d to be clearly superior to two others considered, including optimal u se of the one-unit transfer relation alone.