The Second-Order-Polarization-Propagator-Approximation (SOPPA) in a four-component spinor basis

Anna Kristina Schnack-Petersen*, Mats Simmermacher, Elke Fasshauer, Hans Jørgen Aa Jensen, Stephan P.A. Sauer

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

23 Downloads (Pure)

Abstract

A theoretical framework for understanding molecular structures is crucial for the development of new technologies such as catalysts or solar cells. Apart from electronic excitation energies, however, only spectroscopic properties of molecules consisting of lighter elements can be computationally described at a high level of theory today since heavy elements require a relativistic framework, and thus far, most methods have only been derived in a non-relativistic framework. Important new technologies such as those mentioned above require molecules that contain heavier elements, and hence, there is a great need for the development of relativistic computational methods at a higher level of accuracy. Here, the Second-Order-Polarization-Propagator-Approximation (SOPPA), which has proven to be very successful in the non-relativistic case, is adapted to a relativistic framework. The equations for SOPPA are presented in their most general form, i.e., in a non-canonical spin-orbital basis, which can be reduced to the canonical case, and the expressions needed for a relativistic four-component SOPPA are obtained. The equations are one-index transformed, giving more compact expressions that correspond to those already available for the four-component RPA. The equations are ready for implementation in a four-component quantum chemistry program, which will allow both linear response properties and excitation energies to be calculated relativistically at the SOPPA level.

Original languageEnglish
Article number134113
JournalJournal of Chemical Physics
Volume152
Issue number13
ISSN0021-9606
DOIs
Publication statusPublished - 2020

Fingerprint Dive into the research topics of 'The Second-Order-Polarization-Propagator-Approximation (SOPPA) in a four-component spinor basis'. Together they form a unique fingerprint.

  • Cite this