Isotopic effect of Cl₂⁺ rovibronic spectra in the A-X system

This paper studies the isotopic effect of Cl₂⁺ rovibronic spectra in the A²\Pi_u (\varOmega = 1/2) - X²\Pi_g(\varOmega = 1/2) system. Based on the experimental results of the molecular constants of ³⁵Cl₂⁺, it calculates the vibrational isotope shifts of the (2, 7) and (3, 7) band between the isotopic species ³⁵Cl₂⁺, ³⁵Cl³⁷Cl⁺ and ³⁷Cl₂⁺, and estimates the rotational constants of both A²\Pi_u and X²\Pi_g states for the minor isotopic species ³⁵Cl³⁷Cl⁺ and ³⁷Cl₂⁺. The experimental results of the spectrum of ³⁵Cl³⁷Cl⁺ (3, 7) band proves the above mentioned theoretical calculation. The molecular constants and thus resultant rovibronic spectrum for ³⁷Cl₂⁺ were predicted, which will be helpful for further experimental investigation.