Effects of the potential well on low temperature pressure broadening in CO-He

Previously reported low temperature pressure broadening calculations for CO-He interacting via an SCF-CI potential are compared with new calculations in which the attractive part of the potential is (1) reduced by half and (2) eliminated entirely. Results demonstrate that the attractive well is responsible for low temperature enhancement of pressure broadening cross sections and suggest that agreement with recent experimental values at 4 K can be obtained by a modest reduction, probably within the expected uncertainty, in the attractive part of the SCF-CI potential.