Line mixing in some water vapor transitions perturbed by N2, Ar and He pressure

• Line mixing effect for five pairs of H2O lines perturbed by N2, Ar and He has been studied.
• Half-widths, pressure shifts and off-diagonal relaxation matrix elements have been calculated.
• Calculated data are in satisfactory agreement with measured ones.

Line mixing effect has been studied for five pairs of H2O lines perturbed by N2, Ar and He. Two pairs of lines (in terms of the rotational quantum numbers J, Ka, and Kc) [1 0 1] ← [2 1 2], [2 1 2] ← [3 0 3] and [3 0 3] ← [2 1 2], [2 1 2] ← [1 0 1] belong to the ν2 band, two pairs of lines [3 1 2] ← [4 1 3], [3 2 1] ← [4 2 2] and [4 3 1] ← [3 3 0], [4 2 2] ← [3 2 1], belong to the ν1 + ν2 + ν3 band and fifth pair of the lines [5 4 1] ← [6 5 2], [5 4 1] ← [6 3 4] belong to the 3ν1 + ν2 and 8ν2 band, respectively. Pressure broadening coefficients of H2O (half-widths, pressure shifts and off-diagonal relaxation matrix elements) have been calculated for all lines and for two pair of lines from the ν1 + ν2 + ν3 band perturbed by N2 and Ar they have been obtained experimentally.