Abstract
We develop a new family of electronic structure methods for capturing at the same time the dynamic and nondynamic correlation effects. We combine the natural orbital functional theory (NOFT) and many-body perturbation theory (MBPT) through a canonicalization procedure applied to the natural orbitals to gain access to any MBPT approximation. We study three different scenarios: corrections based on second-order Møller-Plesset (MP2), random-phase approximation (RPA), and coupled-cluster singles doubles (CCSD). Several chemical problems involving different types of electron correlation in singlet and multiplet spin states have been considered. Our numerical tests reveal that RPA-based and CCSD-based corrections provide similar relative errors in molecular dissociation energies (De) to the results obtained using a MP2 correction. With respect to the MP2 case, the CCSD-based correction improves the prediction, while the RPA-based correction reduces the computational cost.
| Original language | English |
|---|---|
| Pages (from-to) | 7562-7574 |
| Number of pages | 13 |
| Journal | JCTC : Journal of chemical theory and computation |
| Volume | 17 |
| Issue number | 12 |
| Early online date | 21 Nov 2021 |
| DOIs | |
| Publication status | Published - 14 Dec 2021 |
Bibliographical note
Funding Information:The authors acknowledge P.-F. Loos and J.W. Hollett for sharing their FCI data. M.R.-M. acknowledges S. Sitkiewicz for his aid on CASPT2 calculations. F.B. and M.R.-M. acknowledge the financial support of the Cross-Disciplinary Program on Numerical Simulation of CEA, the French Alternative Energies and Atomic Energy Commission. M.P. acknowledges the financial support of MCIU/AEI/FEDER, UE (PGC2018-097529-B-100), and Eusko Jaurlaritza (Ref. IT1254-19). I.M. acknowledges a DOKBERRI 2020 II grant from the University of the Basque Country (UPV/EHU).
Publisher Copyright:
© 2021 American Chemical Society.
Funding
The authors acknowledge P.-F. Loos and J.W. Hollett for sharing their FCI data. M.R.-M. acknowledges S. Sitkiewicz for his aid on CASPT2 calculations. F.B. and M.R.-M. acknowledge the financial support of the Cross-Disciplinary Program on Numerical Simulation of CEA, the French Alternative Energies and Atomic Energy Commission. M.P. acknowledges the financial support of MCIU/AEI/FEDER, UE (PGC2018-097529-B-100), and Eusko Jaurlaritza (Ref. IT1254-19). I.M. acknowledges a DOKBERRI 2020 II grant from the University of the Basque Country (UPV/EHU).
