Perturbative approximations to single and double spin flip equation of motion coupled cluster singles doubles methods
| Title | Perturbative approximations to single and double spin flip equation of motion coupled cluster singles doubles methods |
| Publication Type | Journal Article |
| Year of Publication | 2013 |
| Authors | Dutta, AKumar, Pal, S, Ghosh, D |
| Journal | Journal of Chemical Physics |
| Volume | 139 |
| Issue | 12 |
| Pagination | 124116 |
| Date Published | SEP |
| ISSN | 0021-9606 |
| Abstract | Spin flip equation of motion coupled cluster (EOM-SF-CC) can correctly treat situations involving electronic degeneracies or near degeneracies, e. g., bond breaking, di- and tri-radicals, etc. However, for large systems EOM-SF-CC (even in single and double excitations) is computationally prohibitively expensive. Therefore, earlier approximations to EOM-SF-CC methods such as spin flip configuration interaction singles with perturbative doubles (SF-CIS(D)) have been proposed. In this work, we present a new perturbative approximation to EOM-SF-CC, which has been found to be more accurate than SF-CIS(D). The capabilities, advantages, and timings of the new approach have been demonstrated considering the singlet-triplet gaps in di- and triradicals as well as bond breaking examples. The method is extended to double spin flip EOM-CC and its capabilities have been tested. (C) 2013 AIP Publishing LLC. |
| DOI | 10.1063/1.4821936 |
| Type of Journal (Indian or Foreign) | Foreign |
| Impact Factor (IF) | 3.122 |
