The potential of the ground state of NaRb

Abstract

The X${}^1{\Sigma }^{+}$ state of NaRb was studied by Fourier transform spectroscopy. An accurate potential energy curve was derived from more than 8800 transitions in isotopomers ${}^{23}$Na${}^{85}$Rb and ${}^{23}$Na${}^{87}$Rb. This potential reproduces the experimental observations within their uncertainties of 0.003 \rcm to 0.007 \rcm. The outer classical turning point of the last observed energy level ($v^{\prime \prime }=76$, $J^{\prime \prime }=27$) lies at $\approx 12.4$ Å, leading to a energy of 4.5 \rcm below the ground state asymptote.

8 pages, 6 figures and 2 tables