Knowledge Bank

The vibrational levels $v\prime \prime$ - 0 - 12 of the (ground state) Van der Waals ‘ molecule, $Mg2$, were observed and analyzed by Balfour and $Douglas.1$ It was subsequently shown that the outer turning points of the higher observed levels were sensitive to the $R-6$ and $R-8$ terms of the long-range $potential.2$ We have reexamined a plate of the $Mg2$ spectrum generously made available to us by Balfour and Douglas and obtained analyses of two bands involving $v\prime \prime =13$. We have constructed new RKR potentials up to $v\prime \prime =13$ for various values of J(14, 20, 32) which have turning points at distances as large as 8.21 \AA. The analysis of these data to obtain improved values of the dissociation limit and of the $C8$ coefficient is in progress and will be reported.