Strategies for extending geminal-based wavefunctions: Open shells and beyond

Publication date: 15 September 2017 Source:Computational and Theoretical Chemistry, Volume 1116 Author(s): Paul A. Johnson, Peter A. Limacher, Taewon D. Kim, Michael Richer, Ramón Alain Miranda-Quintana, Farnaz Heidar-Zadeh, Paul W. Ayers, Patrick Bultinck, Stijn De Baerdemacker, Dimitri Van Neck We discuss some strategies for extending recent geminal-based methods to open-shells by replacing the geminal-creation operators with more general composite boson creation operators, and even creation operators that mix fermionic and bosonic components. We also discuss the utility of symmetry-breaking and restoration, but using a projective (not a variational) approach. Both strategies—either together or separately—give a pathway for extending geminals-based methods to open shells, while retaining the computational efficiency and conceptual simplicity of existing geminal product wavefunctions. Graphical abstract

Source: Computational and Theoretical Chemistry - August 9, 2017 Category: Chemistry Source Type: research