COMPLEX SCALING OF AB-INITIO MOLECULAR-POTENTIAL SURFACES

The energies and lifetimes (i.e., inverse decay rates) of resonance (q uasibound) states in chemical reactions are associated with the comple x eigenvalues of the complex scaled Hamiltonian. The corresponding eig enfunctions are square integrable and are compact, localized functions in the coordinate space. Complex scaling is applicable when the poten tial, V(x), is dilation analytic. Ab initio potentials, however, are g iven on a grid, V-n= V(x(n)). Starting from the theoretical work of Mo iseyev and Hirschfelder [J. Chem. Phys. 88, 1063 (1988)], we propose a n efficient numerical method of calculating V(x(n) exp(i theta)) by ac ting on the unsealed potential with a grid represented scaling operato r (S) over cap. (C) 1996 American Institute of Physics.