High-resolution Fourier transform spectrum of H2S in the region of the second hexade

High-resolution Fourier transform infrared spectrum of H232S was recorded and analyzed in the region of the second hexade v=v1+12v2+v3=2.5. More than 1700 transitions were assigned to the 2ν1 + ν2, ν1 + ν2 + ν3, ν1 + 3ν2, 3ν2 + ν3, 5ν2, and ν2 + 2ν3 bands with the maximum value of quantum number J equal to 18, 18, 13, 11, 13, and 9, respectively. The theoretical analysis was fulfilled with a Hamiltonian model which takes into account numerous resonance interactions between all the vibrational states in this polyad. By a least-square fitting, finally 505 upper energy levels were reproduced by 80 parameters with an rms deviation of 0.0019 cm−1.