The microwave spectrum and rotational structure of the 1∆ and 3Σ electronic states of sulfur monoxide
The spectrum of 1∆ and 3Σ SO has been studied in the millimeter and submillimeter region of the microwave spectrum. This expanded spectral coverage has made possible the measurement of twenty-two previously unobserved transitions, several of which are necessary for an accurate calculation of the energy levels. As a result, it is now possible to calculate the rotational transitions between energy levels for which J ≤ 10 in both the ground 3Σ electronic state and the excited 1∆ electronic state to an accuracy comparable to that of the microwave measurements themselves (≲ 1 MHz). Among the molecular constants calculated are; for the 1∆ state: B0 = 21 295.405 MHz, D0 = 0.0350 MHz, ωe = 1108 cm -1, and r 0 = 1.4920 Å; and for the 3Σ state: B0 = 21 523.561 MHz, D0 = 0.03399 MHz, λ 0 = 158 254.387 MHz, γ 0 = -168.342 MHz, ϱ0 = 0.305 MHz, r 0 = 1.4840 Å, Be = 21 609.552 MHz, λ e = 157 779.2 MHz, and r e = 1.4811 Å.