High-precision Hy-CI and E-Hy-CI studies of atomic and molecular properties

Ruiz MB, Sims JS, Padhy B (2021)

Publication Type: Book chapter / Article in edited volumes

Publication year: 2021

Journal

Advances in Quantum Chemistry Elsevier Science B.V. Amsterdam

Publisher: Academic Press Inc.

Edited Volumes: Advances in Quantum Chemistry

Series: Advances in Quantum Chemistry

DOI: 10.1016/bs.aiq.2021.05.010

Abstract

This review presents a survey of the most important achievements in atomic and molecular calculations obtained with the Hylleraas-configuration interaction method (Hy-CI) and its extension, the exponentially correlated Hylleraas-configuration interaction method (E-Hy-CI), explaining what led to it and discussing the main mathematical and computational issues. We stress the importance of representing the electronic cusp well in the wave function, which a configuration interaction (CI) wave function does not do, along with the shortcomings of other implicitly correlated wave functions with respect to this cusp. There follows a short review of the types of explicitly correlated wave functions, culminating with an exploration of a generalization of the Hy-CI first proposed in a previous study, the exponentially correlated Hylleraas-configuration interaction method (E-Hy-CI) in which the single rij of an Hy-CI wave function is generalized to a form of the generic type rijνije−ωijrij. We include (1) atomic calculations on states of the He through B atoms using the Hy-CI method, including atomic spectra and isoelectronic ions and the first atomic calculations on the ground state of the He atom employing the E-Hy-CI method, (2) molecular calculations by the Hy-CI method of the H2 molecule using both Slater-type and Gaussian-type orbitals, and (3) calculations of various atomic and molecular properties beyond the energy.

Authors with CRIS profile

Maria Belen Ruiz Ruiz Lehrstuhl für Theoretische Chemie

Involved external institutions

National Institute of Standards and Technology (NIST) US United States (USA) (US) Khallikote Autonomous College IN India (IN)

How to cite

APA:

Ruiz, M.B., Sims, J.S., & Padhy, B. (2021). High-precision Hy-CI and E-Hy-CI studies of atomic and molecular properties. In Advances in Quantum Chemistry. Academic Press Inc..

MLA:

Ruiz, María Belén, James S. Sims, and Bholanath Padhy. "High-precision Hy-CI and E-Hy-CI studies of atomic and molecular properties." Advances in Quantum Chemistry. Academic Press Inc., 2021.

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