Is Externally Corrected Coupled Cluster Always Better Than the Underlying Truncated Configuration Interaction?
| Autor: | Jun Shen, Ilias Magoulas, J. Emiliano Deustua, Karthik Gururangan, Piotr Piecuch |
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| Rok vydání: | 2021 |
| Předmět: |
Chemical Physics (physics.chem-ph)
Nuclear Theory 010304 chemical physics Computation FOS: Physical sciences Computational Physics (physics.comp-ph) Configuration interaction 01 natural sciences Computer Science Applications Nuclear Theory (nucl-th) Moment (mathematics) Amplitude Coupled cluster Operator (computer programming) Physics - Chemical Physics 0103 physical sciences Cluster (physics) Applied mathematics Physical and Theoretical Chemistry Wave function Physics - Computational Physics Mathematics |
| Zdroj: | Journal of Chemical Theory and Computation. 17:4006-4027 |
| ISSN: | 1549-9626 1549-9618 |
| DOI: | 10.1021/acs.jctc.1c00181 |
| Popis: | The short answer to the question in the title is 'no'. We identify classes of truncated configuration interaction (CI) wave functions for which the externally corrected coupled-cluster (ec-CC) approach using the three-body ($T_{3}$) and four-body ($T_{4}$) components of the cluster operator extracted from CI does not improve the results of the underlying CI calculations. Implications of our analysis, illustrated by numerical examples, for the ec-CC computations using truncated and selected CI methods are discussed. We also introduce a novel ec-CC approach using the $T_{3}$ and $T_{4}$ amplitudes obtained with the selected CI scheme abbreviated as CIPSI, correcting the resulting energies for the missing $T_{3}$ correlations not captured by CIPSI with the help of moment expansions similar to those employed in the completely renormalized CC methods. 70 pages, 4 tables, 2 charts, and 1 figure. Supporting Information as an ancillary file. This article has been accepted for publication in the Journal of Chemical Theory and Computation |
| Databáze: | OpenAIRE |
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