Knowledge Bank

Self-consistent field plus configuration-interaction calculations employing a 9s5p2d Cartesian Gaussian basis contracted to 4s3pld have been performed on the four lowest lying $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma$ states and the $A1\Pi$ state of $C3$. The allowed electronic transition moments have been computed and used in conjunction with the theoretical and available $experimental1$ data to estimate the near UV-visible spectrum of $C3$. The application of these results to the problem of entry into atmospheres of the massive outer planets with carbonaceous heat shields is briefly discussed.