采用多组态相互作用方法及Rayleigh-Ritz变分法，计算了类铍O⁴⁺离子1s²2s2p³P°态的非相对论能量，并详细分析了如何选择质量最好的变分波函数。运用截断变分方法进一步饱和函数空间得到能量的改进量，并考虑相对论修正、质量极化效应等获得了相对论能量计算值。计算结果表明，此理论计算方法可得到高精度的能量计算值。

The Rayleigh-Ritz variational calculation is carried out with a multiconfiguration-interraction wave function on the excited state 1s²2s2p³P° in berylliumlike O⁴⁺. Choosing the basis function with sufficiently high quality get the energy E_b. A restricted variation method is used to extrapolate a better nonrelativistic energy. The relativistic corrections and mass polarization are included. The results are better than other theoretical and agreement with experimental data.