Calculations of Alkane Energies Using Long-Range Corrected DFT Combined with Intramolecular van der Waals Correlation

Abstract

The isodesmic reaction enthalpies of n-alkanes to ethane, which have so far been known to give systematic errors in density functional theory (DFT) calculations, are successfully reproduced using long-range corrected (LC) DFT combined with a local response dispersion (LRD) method, which reveals that the failure of conventional DFT results from the lack of long-range exchange interactions in exchange functionals as well as intramolecular dispersion and medium-range electron correlations in correlation functionals.