Regularized and Opposite Spin-Scaled Functionals from Møller–Plesset Adiabatic ConnectionHigher Accuracy at Lower Cost

• Published in: The journal of physical chemistry letters 2023-09, Vol.14 (38), p.8448-8459
• Main Authors: Daas, Kimberly J., Kooi, Derk P., Peters, Nina C., Fabiano, Eduardo, Della Sala, Fabio, Gori-Giorgi, Paola, Vuckovic, Stefan
• Format: Article
• Language: English
• Subjects: Physical Insights into Chemistry, Catalysis, and Interfaces
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.3c01832

Noncovalent interactions (NCIs) play a crucial role in biology, chemistry, material science, and everything in between. To improve pure quantum-chemical simulations of NCIs, we propose a methodology for constructing approximate correlation energies by combining an interpolation along the Møller–Plesset adiabatic connection (MP AC) with a regularization and spin-scaling strategy applied to MP2 correlation energies. This combination yields c osκos-SPL2, which exhibits superior accuracy for NCIs compared to any of the individual strategies. With the N 4 formal scaling, c osκos-SPL2 is competitive or often outperforms more expensive dispersion-corrected double hybrids for NCIs. The accuracy of c osκos-SPL2 particularly shines for anionic halogen bonded complexes, where it surpasses standard dispersion-corrected DFT by a factor of 3 to 5.