document: An efficient parallel algorithm for the calculation of canonical MP2 energies We present the parallel version of a previous serial algorithm for the efficient calculation of canonical MP2 energies . It is based on the Saebo-Almlof direct-integral transformation , coupled with an efficient prescreening of the AO integrals . The parallel algorithm avoids synchronization delays by spawning a second set of slaves during the bin-sort prior to the second half-transformation . Results are presented for systems with up to 2000 basis functions . MP2 energies for molecules with 400-500 basis functions can be routinely calculated to microhartree accuracy on a small number of processors -LRB- 6-8 -RRB- in a matter of minutes with modern PC-based parallel computers
doc_bio_tags: O O B I O O O O B I I O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O B I O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O