Structure of ${}^{12}\mathrm{Be}$ and ${}^{12}\mathrm{O}$ ground states

Consideration of Coulomb energies for ${}^{12}\mathrm{O}$ and ${}^{12}\mathrm{Be},$ combined with other information, strongly suggests that the ${}^{12}\mathrm{Be}$(g.s.) contains about 52% of the configuration ${}^{10}\mathrm{Be}(\mathrm{g}.\mathrm{s}.\mathrm{})\otimes (2s\frac{1}{2}{)}^2.$