A simple model for scalar relativistic corrections to molecular total atomisation energies. (2nd September 2019)

• Record Type: Journal Article
• Authors: Martin, Jan M. L.; Sylvetsky, Nitai
• Is Part Of: Molecular physics. Volume 117:Number 17(2019)
• Page Start: 2225
• Page End: 2232
• Publication Date: 2019-09-02
• Subjects: Thermochemistry -- scalar relativistic effects -- population analysis -- nature of the chemical bond; Molecules -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Molécules -- Périodiques; Chimie physique et théorique -- Périodiques; 539.6.05
• DOI: 10.1080/00268976.2018.1509147
• Languages: English
• ISSNs: 0026-8976

Abstract

ABSTRACT: Scalar relativistic corrections to atomisation energies of first- and second-row molecules can be rationalised in terms of a simple additive model, linear in changes in atomic s populations. In a sample of 200 first-and second-row molecules, such a model can account for over 98% of the variance (99% for the first-row subset). The remaining error can be halved again by adding a term involving the change in atomic p populations: those coefficients need not be fitted but can be fixed from atomic electron affinity calculations. This model allows a fairly accurate a priori estimate for the importance of scalar relativistic corrections on a reaction energy, at essentially zero computational cost. While this is not a substitute for explicit calculation of Douglas–Kroll–Hess (DKH) or exact two-component (X2C) relativistic corrections, the model offers an interpretative tool for the chemical analysis of scalar relativistic contributions to reaction energies. GRAPHICAL ABSTRACT: