Calculations of near-threshold cross sections for photodissociation of CH plus using the Lanczos algorithm

We combine the Lanczos algorithm with the absorbing-potential method, implemented in a discrete variable representation to calculate the near-threshold photodissociation cross sections of CH+. The method is iterative, based on a continued fraction representation of the Green function and avoids any explicit matrix diagonalization. A very good agreement is found with experiment and close-coupling calculations. (C) 2005 American Institute of Physics.