Accurate heats of formation of polycyclic saturated hydrocarbons predicted by using the XYG3 type of doubly hybrid functionals

Abstract

Polycyclic saturated hydrocarbons (PSHs) are attractive candidates as hydrocarbon propellants. To assess their potential values, one of the key factors is to determine their energy contents, such as to calculate their heats of formation (HOF). In this work, we have calculated HOFs for a set of 36 PSHs including exo-Tricyclo[5.2.1.0 (2,6) ] decane, the principal component of the high-energy density hydrocarbon fuel commonly identified as JP-10. The results from B3LYP, B3LYP-D3BJ, M06-2X, B2PLYP, B2PLYP-D3BJ, and the XYG3 type of doubly hybrid (xDH) functionals are presented. It is demonstrated here that the xDH functionals yield accurate HOFs in good agreement with those from experiments or the G4 theory. In particular, XYGJ-OS, a low scaling xDH functional, is shown to hold the promise for accurate prediction of HOFs for PSHs of larger sizes.

New Insights into the Ion-Specific Behaviors and Design Strategies for Ion–π Interactions

“…The XYG3 type of doubly hybrid DFT The XYG3 61 types of doubly hybrid (xDH) density functional theory (DFT) have been shown to be remarkably accurate in describing noncovalent interactions of the main group elements. [62][63][64][65][66][67][68][69][70][71] Here the XYG3 functional is used to fully optimize all ion-π complexes. The 6-31+G (d) basis set is applied to benzene and the related arene π systems, while the 6-31G(d) basis set is applied to the derivatives of naphthalene, anthracene, and triphenylene.…”

Data Science Approach to Estimate Enthalpy of Formation of Cyclic Hydrocarbons

“… 5 Nevertheless, additional data for complex cyclic hydrocarbons, saturated and unsaturated, have been derived in the recent years. 6 , 7 …”

“…Despite their importance, lesser is known about the oxidation process of cyclic hydrocarbons compared to their aliphatic counterparts, as more theoretical and experimental studies have been concerned with the latter . Nevertheless, additional data for complex cyclic hydrocarbons, saturated and unsaturated, have been derived in the recent years. , …”

“…5 Nevertheless, additional data for complex cyclic hydrocarbons, saturated and unsaturated, have been derived in the recent years. 6,7 Chemical kinetics and molecular thermochemistry studies are of vital importance for the development of kinetic models, which are useful to gain knowledge of the oxidation properties of fuels. Accurate thermochemical properties are critical for combustion modeling, as has been recently proved by vom Lehn et al, 8 who observed that ignition delay of diethyl ether mixtures is more sensitive to the enthalpy of formation of certain species than to kinetic parameters.…”