GTOBAS: fitting continuum functions with Gaussian-type orbitals

GTOBAS is a program for fitting Gaussian-type orbitals (GTOs) to Bessel and Coulomb functions over a finite range. The exponents of the GTOs are optimized using the method of Nestmann and Peyerimhoff [J. Phys. B 23 (1990) L773]. The appended module NUMCBAS provides the numerical Bessel and Coulomb functions required as input for the program. The use of GTO continuum basis sets is particularly important in electron-molecule scattering calculations when polyatomic targets are involved. Sample results for such calculations are also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.