Title:
Hybrid correlation models based on active-space partitioning: Seeking accurate O(N ⁵) ab initio methods for bond breaking
Hybrid correlation models based on active-space partitioning: Seeking accurate O(N ⁵) ab initio methods for bond breaking
| dc.contributor.author | Bochevarov, Arteum D. | en_US |
| dc.contributor.author | Temelso, Berhane | en_US |
| dc.contributor.author | Sherrill, C. David | en_US |
| dc.contributor.corporatename | Georgia Institute of Technology. Center for Organic Photonics and Electronics | en_US |
| dc.contributor.corporatename | Georgia Institute of Technology. Center for Computational Molecular Science and Technology | en_US |
| dc.contributor.corporatename | Georgia Institute of Technology. School of Chemistry and Biochemistry | en_US |
| dc.date.accessioned | 2013-04-03T17:57:52Z | |
| dc.date.available | 2013-04-03T17:57:52Z | |
| dc.date.issued | 2006-08 | |
| dc.description | © 2006 American Institute of Physics. The electronic version of this article is the complete one and can be found at: http://dx.doi.org/10.1063/1.2222350 | en_US |
| dc.description | DOI: 10.1063/1.2222350 | en_US |
| dc.description.abstract | Møller-Plesset second-order (MP2) perturbation theory remains the least expensive standard ab initio method that includes electron correlation, scaling as O(N ⁵) with the number of molecular orbitals N. Unfortunately, when restricted Hartree-Fock orbitals are employed, the potential energy curves calculated with this method are of little use at large interatomic separations because of the divergent behavior of MP2 in these regions. In our previous study [J. Chem. Phys. 122, 234110 (2005)] we combined the MP2 method with the singles and doubles coupled cluster (CCSD) method to produce a hybrid method that retains the computational scaling of MP2 and improves dramatically the shape of the MP2 curves. In this work we expand the hybrid methodology to several other schemes. We investigate a new, improved MP2-CCSD method as well as a few other O(N ⁵) methods related to the Epstein-Nesbet pair correlation theory. Nonparallelity errors across the dissociation curve as well as several spectroscopic constants are computed for BH, HF, H₂O, CH+, CH₄, and Li₂ molecules with the 6-31G* basis set and compared with the corresponding full configuration interaction results. We show that among the O(N ⁵) methods considered, our new hybrid MP2-CCSD method is the most accurate and significantly outperforms MP2 not only at large interatomic separations, but also near equilibrium geometries. | en_US |
| dc.identifier.citation | Bochevarov, Arteum D. and Temelso, Berhane and Sherrill, C. David, "Hybrid correlation models based on active-space partitioning: Seeking accurate O(N-5) ab initio methods for bond breaking," Journal of Chemical Physics, 125, 5, (August 7 2006) | en_US |
| dc.identifier.doi | 10.1063/1.2222350 | |
| dc.identifier.issn | 0021-9606 | |
| dc.identifier.uri | http://hdl.handle.net/1853/46622 | |
| dc.publisher | Georgia Institute of Technology | en_US |
| dc.publisher.original | American Institute of Physics | en_US |
| dc.subject | Boron compounds | en_US |
| dc.subject | Water | en_US |
| dc.subject | Hydrogen compounds | en_US |
| dc.subject | Organic compounds | en_US |
| dc.subject | Lithium | en_US |
| dc.subject | Chemical bonds | en_US |
| dc.subject | Ab initio calculations | en_US |
| dc.subject | Perturbation theory | en_US |
| dc.subject | Coupled cluster calculations | en_US |
| dc.subject | Electron correlations | en_US |
| dc.subject | Potential energy surfaces | en_US |
| dc.title | Hybrid correlation models based on active-space partitioning: Seeking accurate O(N ⁵) ab initio methods for bond breaking | en_US |
| dc.type | Text | |
| dc.type.genre | Article | |
| dspace.entity.type | Publication | |
| local.contributor.author | Sherrill, C. David | |
| local.contributor.corporatename | Center for Organic Photonics and Electronics | |
| relation.isAuthorOfPublication | 771cfa30-1ff7-4a12-b4c7-4f8e93b4860a | |
| relation.isOrgUnitOfPublication | 43f8dc5f-0678-4f07-b44a-edbf587c338f |
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