Knowledge Bank

Rational fractions in nuclear separation R have been used to represent the RKR potential V(R) - V($\infty$) for the ground state of $N2$. Variable parameters are adjusted to the best available $C6$ in the long-range $C_{6}/R$6 form, to the Coulomb interaction $7\times 7e2/R$ near R=O, and to the RKR V for the 22 lowest-lying vibrational energy levels. The simplest suitable form, a [1/7] fraction, appears to represent V(R) as accurately as the RKR procedure warrants. Without fitting, V($\infty$) is 2.6% higher than the experimental dissociation limit. With V($\infty$) set equal to $79,850cm-1$, all bound vibrational energies are determined in the first-order WBK approximation. In this approximation there are 63 bound levels. A [1/7] fraction adjusted to the same $C6$ and to a Coulomb pole with nuclear charge Z=7 at R=O, fits the A-state RKR potential as accurately as data warrant. With V($\infty$) fixed at $29,640cm-1$, 38 bound vibrational energies are extracted by WBK intergration. The v=37 level is within $2cm-1$ of the dissociation limit.