Finite element method for two-dimensional vibrational wave functions: Theory and application to van der Waals molecules

Autor: George C. Schatz, Timothy J. Dudley, Rajeev R. Pandey, Mark R. Hoffmann, Philip E. Staffin
Rok vydání: 2001
Předmět:
Zdroj: The Journal of Chemical Physics. 114:6166-6179
ISSN: 1089-7690
0021-9606
Popis: A variational formulation finite element method is developed for calculation of vibrational wave functions in a domain spanned by close-coupled, or Jacobi, coordinates R and γ. C1 tensor-product basis functions, which allow straightforward separation of kinetic and overlap integrals into products of one-dimensional integrals, are used. Furthermore, representation of the potential energy surface in terms of the same tensor-product basis functions used to represent the wave functions allows the potential energy integrals to also be written as a sum of products of one-dimensional integrals. Factorization of the integrals, together with expression of one-dimensional integrals in analytic or rapidly convergent power series form, reduces the computational effort of calculation of all matrix elements to a small, and arguably insignificant, level. It is shown that the theoretical error in eigenvalue, i.e., O(h6) for bicubic Hermite functions, is achieved for a number of rare gas van der Waals triatomics for which...
Databáze: OpenAIRE