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Title: Analytic derivative couplings for spin-flip configuration interaction singles and spin-flip time-dependent density functional theory

Abstract

We revisit the calculation of analytic derivative couplings for configuration interaction singles (CIS), and derive and implement these couplings for its spin-flip variant for the first time. Our algorithm is closely related to the CIS analytic energy gradient algorithm and should be straightforward to implement in any quantum chemistry code that has CIS analytic energy gradients. The additional cost of evaluating the derivative couplings is small in comparison to the cost of evaluating the gradients for the two electronic states in question. Incorporation of an exchange-correlation term provides an ad hoc extension of this formalism to time-dependent density functional theory within the Tamm-Dancoff approximation, without the need to invoke quadratic response theory or evaluate third derivatives of the exchange-correlation functional. Application to several different conical intersections in ethylene demonstrates that minimum-energy crossing points along conical seams can be located at substantially reduced cost when analytic derivative couplings are employed, as compared to use of a branching-plane updating algorithm that does not require these couplings. Application to H{sub 3} near its D{sub 3h} geometry demonstrates that correct topology is obtained in the vicinity of a conical intersection involving a degenerate ground state.

Authors:
Publication Date:
OSTI Identifier:
22420010
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 141; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALGORITHMS; COUPLINGS; DENSITY FUNCTIONAL METHOD; ETHYLENE; GROUND STATES; SPIN FLIP; TIME DEPENDENCE

Citation Formats

Zhang, Xing, and Herbert, John M., E-mail: herbert@chemistry.ohio-state.edu. Analytic derivative couplings for spin-flip configuration interaction singles and spin-flip time-dependent density functional theory. United States: N. p., 2014. Web. doi:10.1063/1.4891984.
Zhang, Xing, & Herbert, John M., E-mail: herbert@chemistry.ohio-state.edu. Analytic derivative couplings for spin-flip configuration interaction singles and spin-flip time-dependent density functional theory. United States. https://doi.org/10.1063/1.4891984
Zhang, Xing, and Herbert, John M., E-mail: herbert@chemistry.ohio-state.edu. 2014. "Analytic derivative couplings for spin-flip configuration interaction singles and spin-flip time-dependent density functional theory". United States. https://doi.org/10.1063/1.4891984.
@article{osti_22420010,
title = {Analytic derivative couplings for spin-flip configuration interaction singles and spin-flip time-dependent density functional theory},
author = {Zhang, Xing and Herbert, John M., E-mail: herbert@chemistry.ohio-state.edu},
abstractNote = {We revisit the calculation of analytic derivative couplings for configuration interaction singles (CIS), and derive and implement these couplings for its spin-flip variant for the first time. Our algorithm is closely related to the CIS analytic energy gradient algorithm and should be straightforward to implement in any quantum chemistry code that has CIS analytic energy gradients. The additional cost of evaluating the derivative couplings is small in comparison to the cost of evaluating the gradients for the two electronic states in question. Incorporation of an exchange-correlation term provides an ad hoc extension of this formalism to time-dependent density functional theory within the Tamm-Dancoff approximation, without the need to invoke quadratic response theory or evaluate third derivatives of the exchange-correlation functional. Application to several different conical intersections in ethylene demonstrates that minimum-energy crossing points along conical seams can be located at substantially reduced cost when analytic derivative couplings are employed, as compared to use of a branching-plane updating algorithm that does not require these couplings. Application to H{sub 3} near its D{sub 3h} geometry demonstrates that correct topology is obtained in the vicinity of a conical intersection involving a degenerate ground state.},
doi = {10.1063/1.4891984},
url = {https://www.osti.gov/biblio/22420010}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 6,
volume = 141,
place = {United States},
year = {Thu Aug 14 00:00:00 EDT 2014},
month = {Thu Aug 14 00:00:00 EDT 2014}
}