We mapped the six-dimensional potential energy surface of the electronic ground state of HCCH(++)(X (3)Sigma(g) (-)) dication using the coupled cluster approach. This potential energy surface isâ€¦ (More)

Various ab initio methods are used to compute the six dimensional potential energy surfaces (6D-PESs) of the ground states of the H(2)NSi and H(2)SiN radicals. They include standard coupled clusterâ€¦ (More)

For electronically degenerate states of linear tetra-atomic molecules, a new method is developed for the variational treatment of the Renner-Teller and spin-orbit couplings. The approach takes intoâ€¦ (More)

We present an ab initio study of the thioketenyl (HCCS) radical in its degenerate X(2)Î electronic ground state. All rotational and vibrational degrees of freedom are taken into account including theâ€¦ (More)

A new variational methodology for the treatment of the Renner-Teller effect in tetra-atomic molecules has been developed in valence coordinates. The kinetic-energy operator of Bramley et al. [Mol.â€¦ (More)

We present a new basis set as an alternative to Legendre polynomials for the variational treatment of bending vibrational degrees of freedom in order to highly reduce the number of basis functions.â€¦ (More)

The variational approach detailed in the previous paper (Paper I) for the treatment of the Renner-Teller effect in linear tetra-atomic molecules including all degrees of freedom and couplings betweenâ€¦ (More)