Singlet geminal wavefunctions

期刊论文
发表日期：

2024年12月4日

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Paul A. Johnson,
Jean-David Moisset,
Marianne Gratton,
Émile Baril,
Marc-Antoine Plourde,
Mathis Lefebvre,
Marianne Kerleaux,
Paul W. Ayers,
Patrick Cassam-Chenaï,
Stijn De Baerdemacker,
Dimitri Van Neck

摘要

Wavefunction forms based on products of electron pairs are usually constructed as closed-shell singlets, which is insufficient when the molecular state has a nonzero spin or when the chemistry is determined by d- or $f-$ $f -$ electrons. A set of two-electron forms are considered as explicit couplings of second-quantized operators to open-shell singlets. Geminal wavefunctions are constructed, and their structure is elaborated. Numerical results for small model systems clearly demonstrate improvement over closed-shell singlet pairs.