N2-broadening coefficients in the ν2 and ν4 bands of PH3

The absorption spectrum of phosphine (PH3) between 2.8 and 3.7μm: Line positions, intensities, and assignments

“…Empirical widths of the assigned lines often fall within 3% of the corresponding calculated values [28,29], but there were a few deviations up to almost 25% for high J, K transitions. For broadening coefficients of the weak unassigned features and forbidden transitions, an uncertainty no better than 30% should be assumed.…”

“…The extensive broadening measurements of the dyad region by Salem et al [10,[28][29][30][31] satisfy many of the current requirements for planetary remote sensing. With a goal of a complete database of phosphine, other studies outside of the scope of this work, such as air-broadened PH 3 coefficients, are necessary for terrestrial applications.…”

“…For assigned allowed transitions, calculated widths for N 2 -and H 2 -broadened PH 3 [28,29] were used; for the forbidden transitions, widths were estimated using values of corresponding transitions with the same the lower state quanta and same values of DJ with DK = 0 or ±1. The temperature dependence of the widths were computed with the expression 0.702 -0.1 · J 00 (lower state J) obtained by Salem et al [30].…”

N2-broadening coefficients in the ν2 and ν4 bands of PH3 at low temperature

“…Here we present only the results derived from the VP and the SDRP since, as previously shown [8], the RP results are located between those results. These broadenings have also been calculated from the semiclassical formalism of Robert and Bonamy [9] by approximating PH 3 as a diatomic molecule for its interaction with N 2 .…”

“…We have recently measured H 2 -broadening coefficients of PH 3 at room [5] and low temperatures [6], self-broadenings [7] as well as N 2 -broadening coefficients at room temperature [8] in the m 2 and m 4 bands. Using a tunable diodelaser spectrometer, we measure in this work N 2 -broadening coefficients of 41 lines of PH 3 at low temperature (À100°C), i.e., 23 lines in the Q R branch of the m 2 band and 18 lines in the P P, R P, and S P branches of the m 4 band.…”