Rotational analysis of the B1Σ+ → X1Σ+ system of H35Cl

Abstract

The B1Σ+ → X1Σ+ system of HCl has been recorded photographically at high resolution in the range 155–250 nm. Rotational assignments of the measured line positions have been made for 39 bands of H35Cl with 0 ≤ ν′ ≤ 6and7 ≤ ν" ≤ 17. Least squares parameter estimates from individual bands have been merged to obtain a set of single-valued parameters that reproduces most of the experimental data to within the measurement precision. First-order Rydberg–Klein–Rees (RKR) turning points for the B and X states are reported from a second set of parameters derived from a truncated data set. The reliability of the ground-state RKR potential is discussed in terms of the first-order approximation and Born–Oppenheimer breakdown. Transitions have been observed to quasi-bound states of several high-lying vibrational levels of the ground state.