A statistical method is introduced to deal with the two-electron energies of a configuration in the detailedterm accounting (DTA) approximation for the spectral line absorption in the radiative opacity of laser-producedplasmas in local thermodynamics equilibrium. The relativistic Hartree-Fock-S1ater self-consistent field averageatom model is used to select the reference ion with most probability and providing basically atomic data. In thisway, fully frequency-dependent and spectral resolved opacity for heavy elements can be obtained readily for theprimary design of radiation transfer in the inertial confinement fusion simulation. Opacities of Au plasmas aregiven.