Study of Hydrogen and Chalcogen Bonds in Chalcogen Hydride Dimers with Self-Interaction Corrected Density Functional Theory

Predicting binding energies for non-covalent interactions, such as for hydrogen (H) or chalcogen (Ch) bonds, is a challenge for DFT methods. This is explained in part by unaccounted dispersion effects, but also by self-interaction errors inherent in all approximate exchange-correlation functionals.  Self-interaction correction (SIC) is known to improve the DFT binding energies for H-bonded water clusters [1] and the PBE results for Ch-bonded systems [2]. However, SIC performance for Ch bonds with other functionals, as well as for the relative energetic ordering of H- and Ch-bonded configurations, has not been studied. We apply SIC methods based on Fermi-Lowdin Orbitals to LSDA, PBE, and r²SCAN calculations for H- and Ch-bonded arrangements of (H₂X)₂ (X = O, S, Se, Te). The predicted binding energies and relative stability of these systems are compared with recent CCSD(T) results [3].  We also discuss the effects of SIC on optimized geometries and the effects of including dispersion corrections. 

[1] K. Sharkas et al., Proc. Natl. Acad. Sci. U. S. A. 117, 11283–11288 (2020)

[2] N. Pangeni et al., ChemRxiv 2025, Preprint, https://doi.org/10.26434/chemrxiv-2025-wfft9

[3] M. P. Hoffman, S. S. Xantheas, J. Am. Chem. Soc. 147, 11152−11171 (2025)