Knowledge Bank

The potential function of the carbon dioxide molecule up to the fourth order of approximation has been determined from the experimental measurements of the vibrational energy levels of $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}C\mathrm{<mrow\; data-mjx-texclass="ORD">16</mrow>}O2$, $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}C\mathrm{<mrow\; data-mjx-texclass="ORD">16</mrow>}O2$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">16</mrow>}O\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}C\mathrm{<mrow\; data-mjx-texclass="ORD">18</mrow>}O$. This function has been applied to the computation of the vibrational energy levels of six additional isotopic species. An illustration of the agreement between these results and the experimental determinations is given along with the spectroscopic constants of these molecules.