Structural and thermochemical properties of the hydroxymethyl $(CH2OH)$ radical: A high precision ab initio study

The variational solution of the $CH2OH$ nuclear problem was performed by treatment of $CH2OH$ as a planar molecule with highly anharmonic vibrations. A sophisticated dynamic model to describe the structural flexibility of $CH2OH$ was applied. The detailed analysis of the rovibrational Hamiltonian is shown. The electron problem solution was obtained by use of the coupled cluster electron correlation technique and the augmented correlation-consistent polarized basis sets of triple- and quadruple-ζ qualities. The geometry and energy parameters were extrapolated to the complete basis set limit. The partition functions of $CH2OH$ were calculated by the explicit summation of vibrational and rotational levels. The heat of formation of $CH2OH,$ $ΔfH∘(298.15 K)=−17.0±0.7 kJ/mol,$ was calculated by a study of the $CH2OH→CH2O+H$ reaction using the augmented basis set of quintuple-ζ quality and the relativistic and core-valence corrections of the total energies. Some structural and thermodynamic properties of $CH2O$ are reported.