Knowledge Bank

We have developed a method based on well established equations that enables us to extract from the wavenumber data of vibration-rotational transitions of diatonic molecules in electronic states $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma$ not only the molecular properties related to the definition of the radial functions for potential energy and related effects but also the electric dipolar moment and the rotational g factor. The latter quantity is related to the magnetisability and thus to the paramagnetic susceptibility independent of temperature, and this infarmation is deduced from only the wavenumber data of multiple isotopic variants even though the spectra are measured, in absorption or emission, for samples without Externally applied electric or magnetic fields. Accurate deductions of these electric and magnetic properties require highly accurate spectral measurements that may include both pure rotational transitions and vibration-rotational transitions, or just the latter. Applications of this method to spectra of diatomic molecules, particularly hydrides including A1H and GaH, will be critically discussed.