Franck-Condon factors,r-centroids and electronic transition moment variation with internuclear distance for AlO (A²∑-X²∑) band system using RKR potentials

Abstract

A comparative study of both RKR and Morse potentials as applied to AlO(A ²∑-X ²∑) band system has been made through various tests. Franck-Condon (FC) factors and r-centroids (r̅_v'v'') with the use of RKR potential have been evaluated and have been employed to derive expression R_e(r) for electronic transition moment variation with internuclear distance r, both by linear and quadratic fitting. Using such R_e(r) relations in conjunction with FC factors and also with experimental band strengths (I/V⁴_v'v''), Smoothed Condon (P_v'v'') factors and β(=I/P_v'v''V⁴_v'v''), the ratio of experimental band strength (I/V_v'v'') to the calculated Smoothed Condon (P_v'v'') factor has been determined. Through the comparison of P_v'v'''s and β's of RKR potential and of Morse potential, the efficacy of Morse potential relative to RKR has been discussed. Vibrational temperatures for all the three thermal sources of excitation of bands, viz. Shock Tube, Low Pressure Arc and Exploding Wire have been deduced both under constancy of R_e and variation of R_e with r. These estimates on vibrational temperatures with the source temperatures have been discussed in the light of the findings of Linton and Nicholls and conclusions regarding relative merits of the two potentials indicated.