Knowledge Bank

Following the "Best Theory + High-resolution Experimental Data" strategy, we have completed an initial CO$2$ infrared (IR) line list, denoted Ames-1. A procedure similar to the one used for ammonia nderline{\textbf129}, 214304 (2008); \textit{J. Chem. Phys.} nderline{\textbf134}, 044320/044321 (2011).} is adopted to generate a global potential energy surface (PES), including various small corrections such as scalar relativity, extrapolation to the one-particle basis-set limit, and a higher-order correlation correction, followed by refinement using accurate high-resolution laboratory data. We will discuss limitations in the use of HITRAN data for the refinement step. The current PES yields uncertainties of 0.01-0.02 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$for \textit{J}=0-117 $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}$C$\mathrm{<mrow\; data-mjx-texclass="ORD">16</mrow>}$O$2$ energy levels up to 13,845 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$ above the zero-point level. Comparisons between Ames-1, HITRAN, and CDSD will be presented for room temperature as well as selected higher temperatures. Results for $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}$C, $\mathrm{<mrow\; data-mjx-texclass="ORD">14</mrow>}$C, $\mathrm{<mrow\; data-mjx-texclass="ORD">17</mrow>}$O, and $\mathrm{<mrow\; data-mjx-texclass="ORD">18</mrow>}$O isotopologues will be presented, and the accuracy for isotopologues will be discussed. Limitations of the current PES and the Ames-1 line list together with strategies to improve these will be discussed.