Evaluation of negative energy Coulomb (Whittaker) functions
Description
Abstract This paper describes a code for evaluating exponentially decaying negative energy Coulomb functions and their first derivatives with respect to the radial variable. The functions, which correspond to Whittaker functions of the second kind, are obtained to high accuracy for a wide range of parameters using recurrence techniques. Title of program: whittaker_w Catalogue Id: ADSZ_v1_0 Nature of problem The closed-channel components of the asymptotic radial wave function corresponding to electron or positron scattering by atomic or molecular ions may be expressed in terms of negative energy Coulomb functions. The scattering observables are obtained from S or T matrices which in turn are obtained by matching the radial and asymptotic wavefunctions at a finite radial point. Recent large scale scattering calculations have required accurate values of the Coulomb functions at smaller ρ values and la ... Versions of this program held in the CPC repository in Mendeley Data ADSZ_v1_0; whittaker_w; 10.1016/j.comphy.2003.12.004 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)