An integral-factorized implementation of the driven similarity renormalization group second-order multireference perturbation theory

作者：Hannon Kevin P; Li Chenyang; Evangelista Francesco A^*

来源：Journal of Chemical Physics, 2016, 144(20): 204111.

DOI：10.1063/1.4951684

We report an efficient implementation of a second-order multireference perturbation theory based on the driven similarity renormalization group (DSRG-MRPT2) [C. Li and F. A. Evangelista, J. Chem. Theory Comput. 11, 2097 (2015)]. Our implementation employs factorized two-electron integrals to avoid storage of large four-index intermediates. It also exploits the block structure of the reference density matrices to reduce the computational cost to that of second-order Moller-Plesset perturbation theory. Our new DSRG-MRPT2 implementation is benchmarked on ten naphthyne isomers using basis sets up to quintuple-zeta quality. We find that the singlet-triplet splittings (Delta(ST)) of the naphthyne isomers strongly depend on the equilibrium structures. For a consistent set of geometries, the Delta(ST) values predicted by the DSRG-MRPT2 are in good agreements with those computed by the reduced multireference coupled cluster theory with singles, doubles, and perturbative triples. Published by AIP Publishing.

• 出版日期2016-5-28