Accurate thermochemistry prediction of extensive Polycyclic aromatic hydrocarbons (PAHs) and relevant radicals

Polycyclic aromatic hydrocarbons (PAHs) are important intermediates to soot formation in combustion. A reliable database of their thermochemistry is required for the development chemical kinetic models describing gas-phase chemistry hydrocarbon fuels. In this study, temperature-dependent thermodynamic properties consistently determined using high-accuracy quantum calculations an extensive set PAH compounds. The developed comprehensively consists 125 C6-C18 molecules and radicals, which commonly included mechanisms studies. At M06-2X/6-311++G(d,p) level theory, geometry optimizations, vibrational frequency calculations, dihedral angle scans performed all species. G3 method, together with atomization reaction approach, selected derive average enthalpy. This method produces most accurate quantities PAHs, as demonstrated a previous study. entropy heat capacity values calculated statistical thermodynamics MultiWell. These results exhibit good agreement databases literature. To examine application group additivity (GA) Bland−Altman plot, analysis employed visualize between from GA methods. Two methods examined significant differences found, indicates that relevant groups need be further updated. study particular value modeling studies exploring growth.