Knowledge Bank

The rotational spectra of the KO radical in the $X2\Pi i$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma$ states were observed in millimeter and sub-millimeter wave region. The KO radical was generated by the reaction of potassium vapor with $N2O$ in a heat pipe cell. Analysis of the observed spectra, with inclusion of interaction terms between the two electronic states, yielded the rotational and centrifugal distortion constants, $\Lambda$-type doubling constants, spin-orbit interaction constant, spin-rotation interaction constants and hyperfine interaction constants in the two electronic states, as well as interaction matrix elements and the energy separation between the two electronic states. We conclude that the ground state is $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\pi i$, and the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma$ states lies $660cm-1$ above the ground state.