Knowledge Bank

The equilibrium geometries, excitation energies force constant and vibrational frequencies for the low-lying electronic states X $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}B1+2A1+,2B2$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}A2$ of the $NCl8$ radical have been calculated at the MRSDCI/DZ--P level. Our calculations indicate that the $X2B1\to 2A2$ transition may correspond to the $X¯\to X¯$ band system which lies between 275--314 mm in absorption spectrum of refs. [1.2]. Our calculated excitation energies for X $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}B2\to 2A1$ AND $X2B1\to 2A2$, vibrational frequencies for the X $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}B1$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}A2$ states and the geometry for the $X2B1$ state are in agreement with available experimental data. The electronic transition dipale moments, oscillator strengths for the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}A2\to X2B1$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}A2\to X1B1$ transitions and radiative lifetimes for the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}A1$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}Ag$ states are calculated based on the MRSDCI wavefunctions, predicting value of the radiative lifetime for the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}A1$ state also in reasonable agreement with experiment.