Experimental and Theoretical Studies of the HeICl Van der Waals Complexes in the Valence and Ion-pair States

The article presents results of experimental and theoretical analysis of the T-shaped and linear HeICl van der Waals complexes in the valence A1 and ion-pair β1 states as well as the HeICl(A1,v_A,n_A←X0⁺,v_X=0,n_x and β1,v_β,n_β←A1,v_A,n_A) optical transitions (n_i are quantum numbers of the vdW) modes). The HeICl(β1,v_β,n_β)→He+ICl(E0⁺, , β1) decay are also studied. Luminescence spectra of the HeICl(β1,v_β=0–3,n_β) complex electronic (ICl(E0⁺,v_E, ) and vibrational ICl(β1,v_β) predissociation products are measured, and branching ratios of decay channels are determined. To construct potential energy surfaces for the HeICl(A1, β1) states, we utilized the intermolecular diatomic-in-molecule perturbation theory first order method. Experimental and calculated spectroscopic characteristics of the A1 and β1 states agree well. Comparison of the experimental and calculated pump-probe, action and excitation spectra shows that the calculated spectra describe the experimental spectra adequately.