Accuracy of enthalpies of formation of hydrocarbons using the SVECV-f12 protocol and comparison to other composite methods

A recently developed composite chemical model, SVECV-f12, intended for a simple and accurate reproduction of barrier heights, is used to determine the energies of atomization and enthalpies of formation of 27 hydrocarbon species included in the W4-17 dataset. The values are compared to the highly accurate W4 theoretical values on one side, and to the enthalpies of formation in the Active Thermochemical Tables on the other. In both cases it is found that there is systematic error which can be easily corrected by a linear correlation. After correction, an r.m. s. deviation of 3.60 kJ mol- 1 was obtained with respect to the W4 values, and 3.48 kJ mol- 1 with espect to the ATcT values. The procedure was then applied to cases in which a large deviation exists between experimental and theoretical data in the literature, further applied to the prediction of the enthalpy of formation of other hydrocarbons which experimental values are unknown, as well as to obtaining hydrogenation and isomerization enthalpies for small-size hydrocarbons.

Automated summary

A composite chemical model, SVECV-f12, has been developed to accurately reproduce barrier heights of hydrocarbon species. The model successfully corrects systematic errors between experimental and theoretical values and is used for predicting formation enthalpies and hydrogenation/isomerization enthalpies.