Experimental and predicted Ag_2 B^1∏_u-X^1∑^+_g absorption band strengths

Relative intensities in the absorption spectrum of the B^1∏_u–X^1∑^+_g band system of diatomic silver are measured for the first time. Analysis of these measurements is performed using Rydberg–Klein–Rees potential curves derived from the best available vibrational and rotational constants for this band system. Comparison of measured and calculated absorption band strength ratios for eleven vibrational bands reveals that the relative electronic transition moment function (ETMF) of the Ag_2 B–X system has a negative slope and decreases by ≈ 40% over the 2.43–2.58 Å range of internuclear distance. The ETMF shows some nonlinear structure; however, the empirical error bars suggest that a linear model is appropriate, thus allowing the r-centroid approximation as a simplification in our analysis.