Recent Advances in the Theory of Vibration–Rotation Hamiltonians

Computational study of adsorption and the vibrational properties of water on the Cu(110) surface

“…For the kinetic energy operator, we have used the exact kinetic energy operator for the gas phase water molecule with the equilibrium geometry of the adsorbed molecule. Vibrational kinetic energy operator of the gas phase water molecule is [23] …”

“…We have applied an appropriate unitary similarity transformation to the kinetic energy operator in order to have a unit weight factor J in the volume element [23]. The g-matrix elements are presented, for example, in reference by HREELS [8], [12].…”

Vibrational energy levels for symmetric and asymmetric isotopomers of ammonia with an exact kinetic energy operator and new potential energy surfaces

“…1 The potential energy surface determines the accuracy of the variationally calculated eigenvalues within the Born-Oppenheimer approximation when an exact kinetic energy operator is used. It is possible to reach almost spectroscopic accuracy in calculations for three-atomic molecules ͑up to ten electrons͒ using pure ab initio potentials if corrections due to, for example, non-Born-Oppenheimer terms and relativistic effects are included.…”

A new proof of the molecular Hamiltonian in Radau coordinates for triatomic molecules based on tensor form

“…The initial step in any theoretical study of many topics in spectroscopy and molecular reaction dynamics is based on the existence of an appropriate Hamiltonian [1][2][3]. In most theoretical studies, large amplitude motions are presently used, which have an important effect on spectra.…”