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

摘要: A new vibrational Hamiltonian operator for ammonia is presented. The potential energy part expressed in terms of symmetrized bond-angle valence coordinates and an inversion coordinate, which a function the bond angles. In exact kinetic operator, stretching instead given unsymmetrized displacement coordinates. Six-dimensional surfaces are calculated using high-level ab initio tools, CCSD(T) method with aug-cc-pVQZ aug-cc-pVTZ basis sets. functions constructed two, two-dimensional steps. as Taylor-type series respect to doubly degenerate asymmetric bending This representation along surface totally symmetric ammonia. Vibrational energies variationally finite representation. Employing successive set contractions, it possible o...