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Updated: Aug 19, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Improved modification for the density-functional theory calculation of thermodynamic properties for C-H-O composite
Min Hsien Liu1, Cheng Chen, Yaw Shun Hong
1Department of Applied Chemistry, Chung Cheng Institute of Technology, National Defense University, Ta Hsi, Taoyuan 33509, Taiwan, Republic of China. mcliu@ccit.edu.tw
Abstract:
A three-parametric modification equation and the least-squares approach are adopted to calibrating hybrid density-functional theory energies of C(1)-C(10) straight-chain aldehydes, alcohols, and alkoxides to accurate enthalpies of formation DeltaH(f) and Gibbs free energies of formation DeltaG(f), respectively. All calculated energies of the C-H-O composite compounds were obtained based on B3LYP6-311++G(3df,2pd) single-point energies and the related thermal corrections of B3LYP6-31G(d,p) optimized geometries. This investigation revealed that all compounds had 0.05% average absolute relative error (ARE) for the atomization energies, with mean value of absolute error (MAE) of just 2.1 kJ/mol (0.5 kcal/mol) for the DeltaH(f) and 2.4 kJ/mol (0.6 kcal/mol) for the DeltaG(f) of formation.
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