Photodetachment microscopy of the P, Q, and R branches of the OH(-)(v=0) to OH(v=0) detachment threshold.

A photodetachment experiment is performed on the v=0-->v=0 OH(-) detachment threshold. The weak O and S branches provide a signal strong enough to make amplitude measurements on all five O, P, Q, R, and S branches possible, which are used to fix the formulas for their relative intensities. Photodetachment microscopy is applied to 15 different thresholds of the P, Q, and R branches. The quantitative analysis of the interference patterns obtained does not show any effect of the dipole moment of OH, but yields a new measurement of the rotational parameters of OH(-)(v=0) and of the electron affinity of the molecule. The new recommended value for the electron affinity of (16)O(1)H is 14 740.982(7) cm(-1) or 1.827 648 7(11) eV.