Dipole moment surfaces and the mid- and far-IR spectra of N-2-Ar

An improved theoretical long-range dispersion plus induction dipole moment surface for N-2-Ar is presented, and detailed numerical simulations are use d to test its predictions against experimental far-IR and mid-IR spectra us ing two previously-reported potential energy surfaces. As was found in earl ier work on the mid-IR spectrum using a pure induction dipole surface, the MMSVmod potential of Jager [J. Chem. Soc. Faraday Discuss. 97, 105 (1994)] yields distinctly better agreement with both experiments than does the XC-3 potential of Dham [J. Chem. Phys. 103, 8477 (1995)]. However, the new dipo le surface yields slightly poorer agreement with certain features of the ex perimental mid-IR and far-IR spectra, which suggests that the existing theo retical values and derivatives with respect to the bond length of some of t he permanent moment and (hyper)polarizability properties of N-2 need improv ement. (C) 2000 American Institute of Physics. [S0021- 9606(00)00725-X].