A method for using a single K-independent grid for problems where otherwise a basis of associated Legendre functions or the corresponding K-dependent grids would be employed, specifically for calculating the rotational-vibrational energy levels of a triatomic molecule, has been described and tested. K independence has been achieved by the incorporation of the weight functions of associated Legendre functions into the Hamiltonian. Exact analytical expressions, valid for any DVR basis, of the matrix elements of the rotation-bending kinetic energy operator (in terms of scattering coordinates) have been given. Simple numerical tests demonstrate that this new method is a useful alternative to the methods proposed so far.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry