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Efficient ab initio Estimation of Formation Enthalpies for Organic Compounds: Extension to Sulfur and Critical Evaluation of Experimental Data

Published

Author(s)

Eugene Paulechka, Andrei F. Kazakov

Abstract

The efficient protocol for estimation of gas-phase enthalpies of formation developed previously for C, H, O, N, and F elements was extended to sulfur. The protocol is based on local coupled-cluster with single, double, and perturbative triple excitations (CCSD(T)) approximation and allows rapid evaluation of compounds with sizes computationally prohibitive to canonical CCSD(T). As a part of model development, a comprehensive review and critical evaluation of experimental data was performed for 85 sulfur-containing organic and inorganic compounds. A compact model with only three empirical parameters for sulfur introduced to address the effects beyond frozen-core CCSD(T) was developed. The model exhibits about 2\kjmol} standard deviation over a set of experimental values for a diverse collection of sulfur-containing compounds. Multiple problems with the existing experimental data were identified and discussed. In addition, a lack of reliable data for certain important classes of sulfur compounds, especially organic sulfates and sulfites, was found to impede the model generalization and confident performance assessment.
Citation
Journal of Physical Chemistry A

Keywords

local coupled cluster method, large-scale predictions, organosulfur compounds, enthalpy of formation

Citation

Paulechka, E. and Kazakov, A. (2021), Efficient ab initio Estimation of Formation Enthalpies for Organic Compounds: Extension to Sulfur and Critical Evaluation of Experimental Data, Journal of Physical Chemistry A, [online], https://doi.org/10.1021/acs.jpca.1c05882, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932253 (Accessed December 7, 2021)
Created September 1, 2021, Updated September 15, 2021