Broadening of hydrogen fluoride lines by H2, D2, and N2

Abstract

Foreign gas broadening of the vibration‐rotation lines in the first overtone band of hydrogen fluoride have been investigated. Linewidths broadened by N₂, H₂, and D₂ have been measured for 15 lines in the band at a resolution of approximately 0.1 cm⁻¹. Comparison of the measured widths with predictions based on the Anderson theory show good agreement only for N₂ broadening of the lower J transitions. Theory overpredicts all H₂ broadened widths and all D₂ broadened widths except those for the R(0), P(1), and P(2) lines for the Anderson treatment of close collisions. Better agreement is found with H₂ broadening if the Van‐Kranendonk treatment of close collisions is used. The general conclusion reached is that the theory cannot be used reliably to predict vibration‐rotation linewidths which are dominated by forces of shorter range than dipole‐dipole.