Determination of Interatomic Potentials for the X0+, A0+, and B1 States of HgKr from Fluorescence and Excitation Spectra

Abstract

We present an analysis of the A0+(63P1)→X0+(61S0) bound–bound and bound–free fluorescence spectrum, and of the A0+(63P1)←X0+(61S0) and B1(63P1)←X0+(61S0) bound–bound excitation spectrum of the HgKr van der Waals molecule. The A→X fluorescence spectrum, which was observed for the first time, as well as the excitation spectra were recorded using a pulsed supersonic molecular beam crossed with a pulsed dye laser beam. An analysis of the A(v′)←X(v″), B(v′)←X(v″), and A(v′=8)→X(v″) bound–bound bands indicates that a Morse function combined with a long-range approximation represents the interatomic potential energy curve of the A, B, and X states below the dissociation limit. In the simulation of the A(v′=8)→X bound–free spectrum the Morse, Lennard-Jones (n-6), and Maitland-Smith (n0, n1) functions were tested, and the Maitland-Smith (11.39, 10.50) potential was found to be a good representation of the repulsive part of the X-state PE curve above the dissociation limit, over the internuclear separation range R=2.85–3.55 Å. The spectroscopic characteristics for the A, B, and X states obtained in this work are compared with other available experimental and theoretical results.