The electron affinity of boron, carbon, nitrogen, and oxygen atoms has been calculated by the method of Bacher and Goudsmit which enables the energy of a state in an $n$-electron configuration to be calculated in terms of the spectroscopic values of the energies of states of the $\mathrm{}(n-1\mathrm{})-, \mathrm{}(n-2\mathrm{})-, \dots$, 1-electron ions. The negative ions of boron and nitrogen are found to be unstable, the electron affinity being $\mathrm{ca}$ - 0.14 and - 0.72 ev, respectively. The electron affinities of carbon and oxygen atoms are 1.75 and 1.13 ev, respectively. The last value is in fair agreement with the recently observed values, 1.48 ev found by Branscomb and Smith, and 1.05 found by Schüler and Bingel.

• Received 11 July 1955

DOI:https://doi.org/10.1103/PhysRev.100.1195