Strengths and Self-Broadened Widths of the Lines of the Hydrogen Bromide Fundamental Band

The strengths and self‐broadened half‐widths of the lines of the fundamental band of HBr have been measured by a curve‐of‐growth method. The method uses a correction for two overlapping lines recently devised by Sakai. The squares of the electric dipole matrix elements, $|{\mathcal{M}}_0^1{\mathrm{(m)|}}^2$ , for the lines have been calculated from the strengths. From the theory of Herman and Wallis and $|{\mathcal{M}}_0^1{\text{(0)|}}^2$ , the dipole moment derivative M₁ is found to be 0.468×10^—10 esu. From the slope at m = 0 of $|{\mathcal{M}}_0^1{\mathrm{(m)|}}^2$ the vibration—rotation interaction parameter, θ, is found to be 1.20. The dependence of the strengths on rotational quantum number J is compared to the J dependence of the strengths of the other hydrogen halides and is compared to theory. A similar comparison is made for the J dependence of the half‐widths.