An Approximate Calculation of the Lower Energy Levels of the Carbon Atom

Slater's theory of the complex atom as modified and extended by Zener and Eckart is applied to the $2p^2$ and $2p^3$ configurations of the carbon atom. The energy levels resulting from these configurations are computed. Some of the computed energy differences agree roughly with the experimental values, others indicate either that the method is not applicable or that the experimental data are not reliable. The $2p^3$, ${}_{}{}^5{}_{}{}^{}S$level is found to lie nearest to the normal $2p^2$, ${}_{}{}^3{}_{}{}^{}P$ level. Of the levels for which experimental data are lacking or doubtful, the $2p^3$, ${}_{}{}^1{}_{}{}^{}D$ is computed to lie 12.9 volts above the normal, the $2p^3$, ${}_{}{}^3{}_{}{}^{}S$, 13.7 volts and the $2p^3$, ${}_{}{}^1{}_{}{}^{}P$, 14.7 volts above the normal.