S. Mahapatra et N. Sathyamurthy, NEGATIVE IMAGINARY POTENTIALS IN TIME-DEPENDENT QUANTUM MOLECULAR-SCATTERING, Journal of the Chemical Society. Faraday transactions, 93(5), 1997, pp. 773-779
Citations number
62
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Reflection or wrap around of the wavefunction from the grid edges is o
ften avoided in time-dependent quantum mechanical calculations by usin
g a negative imaginary potential (NIP) near the grid edges. The stabil
ity of the various (second-order differencing, split operator, Chebysh
ev polynomial and short iterative Lanczos) schemes used, in conjunctio
n with the NIP, for time evolution is discussed using collinear (He, H
-2(+)) collisions as a test case. It is shown that the difficulties en
countered in obtaining converged reaction probability [P-R(E)] values
at high energies for the system when NIPs are used, are avoided by usi
ng a properly chosen damping function externally.