Knowledge Bank

The lowest Rydberg state of NO has been observed to fluoresce with unity quantum yield in solid Ar, Kr, and Xe hosts. The purely radiative lifetimes lengthen in the sequence of vacuum, Ar, Kr, Xe--thus, directly demonstrating an increasing delocalization of the Rydberg wave function in media with increasing dielectric coefficients. A simple, semiquantitative theory of the relative stability of bubble” and Wannier Rydberg states predicts bubble” $(\sim 10$ {\AA} diameter) formation around low n Rydberg states in the lighter rare gas solids. Asymmetric phonon contours in absorption and fluorescence, as well as the experimental extent of delocalization compared with Wannier model predictions, support ``bubble” formation around NO $3s\sigma (A2\Sigma )$. Sequential two photon excitation spectra from $3s\sigma$ to higher Rydberg states near 7.5 eV are broad in all three hosts. The Rydberg $3s\sigma$ spectra and photophysics are compared with those of the nearly isoenergetic $B2\Pi$ and $a^{4}\Pi $states in both $\mathrm{<mrow\; data-mjx-texclass="ORD">14</mrow>}NO$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">15</mrow>}NO$. The distinction between vertical and adiabatic ionization is discussed.