Low-Temperature Scattering with the R-Matrix Method: The Morse Potential

Abstract

Experiments are starting to probe collisions and chemical reactions between atoms and molecules at ultralow temperatures. We have developed a new theoretical procedure for studying these collisions using the R-matrix method. Here, this method is tested for the atom—atom collisions described by a Morse potential. Analytic solutions for continuum states of the Morse potential are derived and compared with numerical results computed using an R-matrix method, where the inner region wavefunctions are obtained using a standard nuclear motion algorithm. Results are given for eigenphases and scattering lengths. Excellent agreement is obtained in all cases. Progress in developing a general procedure for treating ultralow energy reactive and non-reactive collisions is discussed