Knowledge Bank

By transforming reported potential-energy functions of internuclear distance of $He2,Ne2,Ar2,Kr2,Xe2$, HeNe, HeAr, HeKr, HeXe, NeAr, NeKr, NeXe, ArKr, ArXe and KrXe in their electronic ground states $X1\Sigma g\prime +,1\Sigma +,Og+$ or $O+$ into the form $V(z)$, in which $Z=2(R-Re)/(R+Re)$, we have calculated directly the vibrational and rotational energies of the corresponding bound states for comparison with, or prediction of, experimental data of the same molecules. Because we found a universal relation relating the equilibrium internuclear distance $Re$ and leading coefficient $c0$ in $V(z)$ to the atomic electric dipole polarisabilities, in conjunction with a common set of coefficients, $c_{j}, ^{1}\xi j\xi 10 $ we can confidently predict the vibration-rotational spectral properties of the noble-gas diatomic molecules containing Rn, such as $HeRn,NeRn\dots Rn2$, from only a knowledge or estimate of the atomic polarisability of Rn; the predictions are expected to be more accurate for the lower vibrational states than for those near the dissociation limit. By fitting abundant and precise vibration-rotational spectral data of a diatomic molecule, we have been able to determine coefficients of the applicable radial functions that enable us to predict the rotational dependence of the rotational magnetogyric ratio $gJ$. The application of this procedure to SiS and other molecules will be discussed.