Knowledge Bank

The $X1\Sigma g+$ ground state potential energy surface of $NO2\mathrm{<mrow\; data-mjx-texclass="ORD">+</mrow>}$ has been scanned to obtain the equilibrium geometry, force constants and vibrational frequencies. The wavefunctions were constructed in a 4s2pld one-electron basis set with a twenty configuration MCSCF orbital basis for a full valence configuration expansion. The calculated equilibrium geometry is $RNOe=1.12\pm 0.01$ {\AA}, $AONOe=180\circ$. The bond and bending force constants are $kNO=20.6$ md/{\AA} and $kONO=0.791$ md/{\AA}. Other force constants and the vibrational frequencies will be presented and compared to crystalline spectroscopic studies on $NO2C104$.$\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$ Our results differ significantly from the crystalline results and are, to our knowledge, the best gas phase results available. This work, is part of a project on potential surfaces and spectra for air triatomics now on-going at Science Applications, Incorporated.