Knowledge Bank

We show how we have been able to determine from experimental measurements of vibration-rotation line intensities, some coefficients appearing in the expansion of the dipole moment with respect to normal coordinates. In particular, the combined study of cold” and hot” bands allows to resolve the ambiguity of signs always present in such problems. From the study of the $\nu 2,2\nu 2,\nu 1,\nu 3,\nu 1+\nu 2,\nu 2+\nu 3,\nu 1-\nu 2,\nu 3-\nu 2$ and $2\nu 2-\nu 2$ bands, we have obtained: \begin{eqnarray*} \begin{array}{rlllll} ^{2}\mu_{x}&=& 0.1794_{6}& \pm &0.0020D&(a)\ ^{1}\mu_{x}&=&-0.0217_{0}& \pm &0.0010 D&(b)\ ^{3}\mu_{z}&=& 0.0971_{4} &\pm& 0.0018 D&(b)\ ^{22}\mu_{x}&=& 0.013 &\pm& 0.002 D&(b)\ ^{12}\mu_{x}&=&(-0.843& \pm& 0.18)\times 10^{-1} &D; (c)\ ^{23}\mu_{z}&=& (0.267& \pm& 0.010)\times10^{-1}& D; (c) \end{array} \end{eqnarray*}