Abstract
In Density Functional Theory (DFT) direct dynamics simulations with Unrestricted Hartree Fock (UHF) theory, triplet instability often emerges when numerically integrating a classical trajectory. A broken symmetry initial guess for the wave function is often used to obtain the unrestricted DFT potential energy surface (PES), but this is found to be often insufficient for direct dynamics simulations. An algorithm is described for obtaining smooth transitions between the open-shell and the closed-shell regions of the unrestricted PES, and thus stable trajectories, for direct dynamics simulations of dioxetane and its •OCH2-CH2O• singlet diradical.
| Original language | English |
|---|---|
| Pages (from-to) | 933-936 |
| Number of pages | 4 |
| Journal | Journal of Computational Chemistry |
| Volume | 40 |
| Issue number | 8 |
| DOIs | |
| State | Published - Mar 30 2019 |
| Externally published | Yes |
Funding
The research reported here was supported by the National Science Foundation under Grant No. CHE-1416428, the Robert A. Welch Foundation under Grant No. D-0005, and the Air Force Office of Sci-entific Research under AFOSR Award No. FA9550-16-1-0133. The simulations were performed on the Chemdynm computer cluster of the Hase Research Group and the Lonestar5 cluster of the Texas Advanced Computing Center (TACC) at the University of Texas, Austin. Shreyas Malpathak was supported by a S.N. Bose Fellowship from the S.N. Bose Scholars Program for Indian students. Discussions with Professor Anirban Hazra from the Indian Institute of Science Education and Research, Pune are gratefully acknowledged, as well as those with Professor Rui Sun at the University of Hawaii. The research reported here was supported by the National Science Foundation under Grant No. CHE-1416428, the Robert A. Welch Foundation under Grant No. D-0005, and the Air Force Office of Scientific Research under AFOSR Award No. FA9550-16-1-0133. The simulations were performed on the Chemdynm computer cluster of the Hase Research Group and the Lonestar5 cluster of the Texas Advanced Computing Center (TACC) at the University of Texas, Austin. Shreyas Malpathak was supported by a S.N. Bose Fellowship from the S.N. Bose Scholars Program for Indian students. Discussions with Professor Anirban Hazra from the Indian Institute of Science Education and Research, Pune are gratefully acknowledged, as well as those with Professor Rui Sun at the University of Hawaii. [a] S. Malpathak, X. Ma, W. L. Hase Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, 79409 E-mail: [email protected] [b] S. Malpathak Department of Chemistry, Indian Institute of Science Education and Research, Pune 411008, India Contract Grant sponsor: Air Force Office of Scientific Research; Contract Grant numbers: FA9550-16-1-0133, 0005; Contract Grant sponsor: S. N. Bose Fellowship; Contract Grant sponsor: Welch Foundation; Contract Grant number: D-0005; Contract Grant sponsor: National Science Foundation; Contract Grant number: CHE-1416428
| Funders | Funder number |
|---|---|
| Air Force Office of Sci-entific Research | |
| Lonestar5 cluster of the Texas Advanced Computing Center | |
| Robert A. Welch Foundation | |
| TACC | |
| W. L. Hase Department of Chemistry and Biochemistry | |
| National Science Foundation | CHE-1416428 |
| National Institutes of Health | F06TW000005 |
| Air Force Office of Scientific Research | FA9550-16-1-0133 |
| Welch Foundation | D-0005 |
| Graduate School, University of Texas, Austin | |
| Texas Tech University | |
| Indian Institute of Science Education and Research Mohali |