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Title: Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods

Abstract

An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the COLUMBUS quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbit coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing cuts of the potential energy surfaces of acrolein and its S, Se, and Te analoga with the corresponding data obtained from matching fully variational spin-orbit MRCISD calculations. The conceptual availability of approximate analytic gradients with respect to geometrical displacements is an attractive feature of the 2c-QDPT-MRCISD and 2c-QDPT-LRT-MRAQCC methods for structure optimization and ab inito molecular dynamics simulations.

Authors:
; ;  [1];  [2];  [3];  [1]
  1. Institute of Theoretical Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna (Austria)
  2. Institute for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich (Germany)
  3. Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368, 69120 Heidelberg (Germany)
Publication Date:
OSTI Identifier:
22420118
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 141; Journal Issue: 7; 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; ACCURACY; ACROLEIN; L-S COUPLING; MOLECULAR DYNAMICS METHOD; PERTURBATION THEORY; POTENTIAL ENERGY; SIMULATION; SOLUTIONS; SURFACES

Citation Formats

Mai, Sebastian, Marquetand, Philipp, González, Leticia, Müller, Thomas, Plasser, Felix, Lischka, Hans, and Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061. Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods. United States: N. p., 2014. Web. doi:10.1063/1.4892060.
Mai, Sebastian, Marquetand, Philipp, González, Leticia, Müller, Thomas, Plasser, Felix, Lischka, Hans, & Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061. Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods. United States. https://doi.org/10.1063/1.4892060
Mai, Sebastian, Marquetand, Philipp, González, Leticia, Müller, Thomas, Plasser, Felix, Lischka, Hans, and Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061. 2014. "Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods". United States. https://doi.org/10.1063/1.4892060.
@article{osti_22420118,
title = {Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods},
author = {Mai, Sebastian and Marquetand, Philipp and González, Leticia and Müller, Thomas and Plasser, Felix and Lischka, Hans and Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061},
abstractNote = {An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the COLUMBUS quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbit coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing cuts of the potential energy surfaces of acrolein and its S, Se, and Te analoga with the corresponding data obtained from matching fully variational spin-orbit MRCISD calculations. The conceptual availability of approximate analytic gradients with respect to geometrical displacements is an attractive feature of the 2c-QDPT-MRCISD and 2c-QDPT-LRT-MRAQCC methods for structure optimization and ab inito molecular dynamics simulations.},
doi = {10.1063/1.4892060},
url = {https://www.osti.gov/biblio/22420118}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 7,
volume = 141,
place = {United States},
year = {Thu Aug 21 00:00:00 EDT 2014},
month = {Thu Aug 21 00:00:00 EDT 2014}
}