Evaluation of Density Functionals for Si-O-C-H Molecule Thermochemistry.

ABSTRACT: The energies and vibrational frequencies of molecular species with Si-O-C-H compositions have been calculated at the CCSD(T) level (coupled cluster with single and double excitations and a perturbative treatment of triple excitations). The CCSD(T) results compare well with experimental data where the difference in enthalpy of formation is typically only about 1-2 kJ/mol in most cases. In addition, the same molecules have been calculated with density functional theory (DFT) calculations using nine commonly used density functionals and two different basis sets. The performance of the DFT calculations is compared with the CCSD(T) benchmark values in terms of enthalpy of formation, reaction energy, vibrational frequencies, and zero-point energies. The results show that the M06-2X functional pr

SUBMITTER: Svenum IH 

PROVIDER: S-EPMC12598855 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature