High resolution spectrum of the ν5 band of nitric acid (HNO3) near 880 cm−1

Tunable diode lasers have been used to measure the spectrum of HNO₃ from 853 to 892 cm^?1. A Fermi interaction with the nearby 2ν₉ state perturbs some of the transitions and causes some problems in the analysis, but several hundred lines have been assigned and fit to a set of band constants with a standard deviation of 0.0007 cm^?1. The measurements include most of the P branch, the strongest lines of the Q branch, and some R-branch transitions. Only A-type transitions have been identified and any B-type transitions must be much weaker.