September 30, 2026
Journal Article

H2X100: A Gold-Standard CCSD(T)/CBS Benchmark Dataset of Binding Energies, Structures, and Harmonic Frequencies for (H2X)n, X = S, Se, Te, n = 2 – 4, and Assessment of Lower-Scaling Density Functional Theory Methods

Abstract

We constructed a benchmark dataset (H2X100) of 100 CCSD(T)/Complete Basis Set (CBS) binding energies for the (H2X)n, X=S, Se, Te, n=2-4 clusters and additional CCSD(T)-quality structures and harmonic vibrational frequencies for twelve unique homodimer minima. Using the new H2X100 dataset we assessed the performance of 17 density functionals across the rungs of Jacob’s ladder with and without dispersion corrections spanning the GGA, mGGA, GH-GGA, GH-mGGA, RSH-GGA and RSH-mGGA groupings. The r2SCAN-D4, B97M-rV, and ?B97M-V functionals provide the best agreement with the CCSD(T) benchmarks and can be used in studies of larger assemblies of these systems, including simulations of their condensed phases.

Published: September 30, 2026

Citation

Hoffman M.P., and S.S. Xantheas. 2026. H2X100: A Gold-Standard CCSD(T)/CBS Benchmark Dataset of Binding Energies, Structures, and Harmonic Frequencies for (H2X)n, X = S, Se, Te, n = 2 – 4, and Assessment of Lower-Scaling Density Functional Theory Methods. Journal of Chemical Theory and Computation 22, no. 11:5539–5554. PNNL-SA-221006. doi:10.1021/acs.jctc.6c00405

Research topics

Computational Chemistry