Abstract
We develop and test methods that include second- and third-order perturbation theory (MP3) using orbitals obtained from regularized orbital-optimized second-order perturbation theory, κ-OOMP2, denoted as MP3:κ-OOMP2. Testing MP3:κ-OOMP2 shows RMS errors that are 1.7-5 times smaller than those of MP3 across 7 data sets. To do still better, empirical training of the scaling factors for the second- and third-order correlation energies and the regularization parameter on one of those data sets led to an unregularized scaled (c2 = 1.0; c3 = 0.8) denoted as MP2.8:κ-OOMP2. MP2.8:κ-OOMP2 yields significant additional improvement over MP3:κ-OOMP2 in 4 of 6 test data sets on thermochemistry, kinetics, and noncovalent interactions. Remarkably, these two methods outperform coupled cluster with singles and doubles in 5 of the 7 data sets considered, at greatly reduced cost (no O(N6) iterations).
Original language | English |
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Pages (from-to) | 4170-4176 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry Letters |
Volume | 10 |
Issue number | 15 |
DOIs | |
State | Published - Aug 1 2019 |
Externally published | Yes |
Funding
This work was supported by the U.S. Department of Energy, Office of Basic Energy Science, and Office of Advanced Scientific Computing Research through the SciDAC program.
Funders | Funder number |
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Office of Basic Energy Science | |
U.S. Department of Energy | |
Advanced Scientific Computing Research |