Figure 3: CaH⁺ vibrational overtone spectra.

The measured τ_d are averaged over eight experiments and the inverse is plotted as a function of the IR wavelength. The data reveals two peaks that are fit assuming a Gaussian line shape. Grey bars are centred at the calculated theoretical values²³ for the ν′=10←ν=0 and ν′=9←ν=0 overtones. Error bars are the s.e.m. of r_d=1/〈τ_d〉, , propagated from the s.e.m. of 〈τ_d〉, : .