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Halogen-bond revision6_MKK notrackJM2.docx (245.64 kB)

The X40x10 Halogen Bonding Benchmark Revisited: Surprising Importance of (n-1)d Subvalence Correlation

preprint
revised on 31.01.2018, 17:00 and posted on 31.01.2018, 18:31 by Manoj Kumar Kesharwani, Nitai Sylvetsky, Debashree Manna, Jan M.L. Martin

We have re-evaluated the X40x10 benchmark for halogen bonding using conventional and explicitly correlated coupled cluster methods. For the aromatic dimers at small separation, improved CCSD(T)–MP2 “high-level corrections” (HLCs) cause substantial reductions in the dissociation energy. For the bromine and iodine species, (n-1)d subvalence correlation increases dissociation energies, and turns out to be more important for noncovalent interactions than is generally realized; ; (n-1)sp subvalence correlation is much less important. The (n-1)d subvalence term is dominated by core-valence correlation; with the smaller cc-pVDZ-F12-PP and cc-pVTZ-F12-PP basis sets, basis set convergence for the core-core contribution becomes sufficiently erratic that it may compromise results overall. The two factors conspire to generate discrepancies of up to 0.9 kcal/mol (0.16 kcal/mol RMS) between the original X40x10 data and the present revision.

Funding

Israel Science Foundation 1358/15

History

Email Address of Submitting Author

gershom@weizmann.ac.il

Email Address(es) for Other Author(s)

gershom@weizmann.ac.il

Institution

Weizmann Institute of Science

Country

Israel

ORCID For Submitting Author

0000-0002-0005-5074

Declaration of Conflict of Interest

No conflict of interest declared

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