An integral-factorized implementation of the driven similarity renormalization group second-order multireference perturbation theory
Abstract
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 Møller-Plesset perturbation theory. Our new DSRG-MRPT2 implementation is benchmarked on ten naphthyne isomers using basis sets up to quintuple-ζ quality. We find that the singlet-triplet splittings (ΔST) of the naphthyne isomers strongly depend on the equilibrium structures. For a consistent set of geometries, the ΔST 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.
- Publication:
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Journal of Chemical Physics
- Pub Date:
- May 2016
- DOI:
- 10.1063/1.4951684
- arXiv:
- arXiv:1603.00561
- Bibcode:
- 2016JChPh.144t4111H
- Keywords:
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- Physics - Chemical Physics
- E-Print:
- doi:10.1063/1.4951684