Line strength analysis of the second overtone 3 ν 2 band of D 2 32 S

Highlights: • Experimental line strengths are determined for the 3$v_2$ band of D${}_2$S. • Effective dipole moment parameters of the 3$v_2$ band are obtained. The high resolution infrared spectrum of di–deuterated hydrogen sulfide D${}_2$S was recorded with a Bruker IFS 125HR Fourier transform infrared spectrometer and analyzed in the region of 2400–2900 cm${}^{-1}$ where ro–vibrational bands of the so–called second triad of D${}_2$S are located. The present study is focused on the line strength analysis of the weak $3{\nu }_2$ band which is made for the first time. The strength analysis comprise 300 lines (376 transitions) with maximum values of the quantum numbers $J^{\text{max}}$ = 18 and $K_a^{\text{max}}$ = 9 and was performed by the fit of the experimental line shapes with a Hartmann–Tran profile. The six effective dipole moment parameters of the $3{\nu }_2$ band were obtained from the weighted fit which reproduce the initial experimental line strengths with the $d_{\text{rms}}=3.1\%$.