Self-broadening coefficients and absolute line intensities in the ν4 + ν5 band of acetylene

Self-broadening coefficients and line strengths have been measured at room temperature for 30 lines of C2H2 in the P and R branches of the ν4 + ν5 band, using a tunable diode laser spectrometer. These lines, ranging from P(22) to R(23), are located in the spectral range 1275-1390 cm−1. A semiclassical calculation of the line broadenings has been performed considering the main electrostatic interactions and an anisotropic dispersion contribution leading to results in satisfactory agreement with the experimental data.