EMPIRICAL POTENTIAL-ENERGY SURFACE FOR AR-CENTER-DOT-SH D AND KR-CENTER-DOT-SH/D/

Experimental data from vibrationally and rotationally resolved laser i nduced fluorescence experiments have been used to produce potential en ergy surfaces (PES) for the excited (A) over tilde(2) Sigma(+) states of the AR.SH and Kr.SH van der Waals complexes. This was done using a potential energy functional form first suggested by Bowman and co-work ers [J. Phys. Chem. 94, 2226, 8858 (1990); Chem. Phys. Lett. 189, 487 (1992)] for Ar.OH/D. A discrete variable representation (DVR) of the v ibration-rotation Hamiltonian was used in combination with the implici tly restarted Lanczos method and sequential diagonalization truncation (SDT) of the DVR Hamiltonian. This approach takes advantage of the sp arseness of the DVR Hamiltonian and the reduced order of the SDT repre sentation. This combination of methods greatly reduces the amount of c omputational time needed to determine the eigenvalues of interest. Thi s is important for the determination of the PES that results from mini mizing the difference between the experimental and theoretically predi cted values for the vibronic energy levels and their corresponding rot ational constants. In addition this procedure was helpful in assigning the absolute vibrational quantum numbers for the deuterated species f or which less experimental data was available. Flats of the calculated wavefunctions corresponding to various experimentally vibronic bands indicate that these states sample regions of the PES from 0 degrees, w here the hydrogen atom is closest to the rare gas atom, to approximate ly the saddle point, near the T-shaped configuration. As a result this region of thr surface is determined accurately whereas the region of the PES around 180 degrees, corresponding to the sulfur atom being clo sest to the rare gas atom, is determined only qualitatively. (C) 1997 American Institute of Physics.