Spin-Free [2]R12 Basis Set Incompleteness Correction to the Local Multireference Configuration Interaction and the Local Multireference Average Coupled Pair Functional Methods.
The local multireference configuration interaction (LMRCI) and local multireference averaged coupled pair functional (LMRACPF) methods are extended to include explicit correlation via the universal spin-free [2]R12 basis set incompleteness correction. Four test cases are examined to measure the performance of the LMRCI+[2]R12 (without and with the Davidson + Q correction for size-extensivity) and LMRACPF+[2]R12 methods. These tests examine bond dissociation energies (BDEs) for ethene, perfluoroethene, propene, and 2-butene. As has been demonstrated for other methods, the LMRCI+[2]R12/LMRCI+Q+[2]R12/LMRACPF+[2]R12 BDEs are as accurate as the conventional LMRCI/LMRACPF BDEs that are computed with the basis set one cardinal number higher. It is shown that LMRCI+[2]R12/LMRCI+Q+[2]R12/LMRACPF+[2]R12 BDEs computed with the June calendar basis sets preserve the accuracy of the corresponding BDEs computed with the conventional aug-cc-pVXZ basis sets (where X = D, T, Q).
Department of Chemistry, Iowa State University , Ames, Iowa 50010, United States.
Luke B
LB
Roskop
Department of Chemistry, Virginia Tech , Blacksburg, Virginia 24061, United States.
Edward F
EF
Valeev
Department of Mechanical and Aerospace Engineering, Program in Applied and Computational Mathematics, and Andlinger Center for Energy and the Environment, Princeton University , Princeton, New Jersey 08544, United States.
Emily A
EA
Carter
Department of Chemistry, Iowa State University , Ames, Iowa 50010, United States.
Mark S
MS
Gordon
Department of Chemistry, Iowa State University , Ames, Iowa 50010, United States.
Theresa L
TL
Windus