Binding energy of the lowest state of negative beryllium

Accurate eigenvalues of Schrödinger’s nonrelativistic equation for Be (1$s^2$2s2p${)}^3$P and ${\mathrm{Be}}^{\mathrm{-}}$ (1$s^2$2s2$p^2$ ${)}^4$P have been calculated yielding a corresponding electron affinity A of 276.1±6.5 meV. The absolute term value of ${\mathrm{Be}}^{\mathrm{-}}$ (relative to the Be ground state) obtained as the difference between the experimental term value of Be ${}_{}{}^3{}_{}{}^{}\mathrm{P}$ and A is 2.4492±0.0065 eV, in agreement with a recent measurement of 2.53±0.11 eV.