核自旋和离心扭曲因子对分子跃迁谱线强度的影响研究

The line intensities of 010101g-000011u transition of linear tetratomic molecule C2H2 at temperatures from 2 K to 5000 K were calculated with the theory of molecular spectra. The effects of nuclear-spin and centrifugal distortion constants were calculated and discussed. The results show that the nuclear-spin becomes important only at very low temperatures, below 10 K for C2H2, but its effect increases rapidly as the temperature is lowered further. When the centrifugal distortion is considered, the effect is significant even at moderate temperature, affecting the line intensities by 0.03% at 500 K and by 0.81% at 5000 K. The results are of significance for the accurate calculation of molecular line intensities at different temperatures.

Study of the influences of nuclear-spin and centrifugal distortion constants on the line intensities of acetylene molecule