The Torsional Spectrum of the Hydrogen Trioxide Molecule

Abstract

The energies of the stationary torsional levels of the hydrogen trioxide molecule were calculated at the B3LYP, MP2, and CCSD(T) levels of theory using augmented correlation consistent acc-pVTZ basis set. The molecular symmetry group whose elements are inherent to both equilibrium conformer's symmetry elements (C2 and CS) of the HT molecule was found. Different methods of the molecular parameters calculations were suggested and analyzed. The torsional, spin and total wave functions were classified by irreducible representations of the C2V(M) molecular symmetry group. The 2D dipole moment surface was calculated too. The energies of the stationary torsional states were found using DVR and Fourier methods. With this and acceptable combinations of spatial and spin wave functions, the IR torsional spectrum was calculated at different temperatures. The tunneling frequencies in the ground and some excited torsional states were estimated too.