M2,3spectrum of atomic Mn

The $3p\to 3d$ absorption spectrum of Mn vapor measured by Connerade, Mansfield, and Martin is compared to calculations based upon single-configuration Hartree-Fock multiplet theory and the formalism of Fano for the interaction of discrete and continuum states. It is concluded that the principal decay is through super-Coster-Kronig transitions. The observation of sharp structure associated with the excited states $3p^{5}3d^{6}4s^2\left({}_{}{}^6{}_{}{}^{}D\right)$, for example, is shown to be consistent with this mechanism. Decay selection rules are found to be a consequence of rotation and inversion symmetry. Spin-orbit interaction in the $3p$ subshell is treated exactly to obtain the sharp structure below the giant ${}_{}{}^6{}_{}{}^{}P$ resonance. It is necessary to include the off-diagonal matrix elements of the decay matrix $\Gamma$ to obtain the correct line shape since the resonances overlap. The resonance shift of the Hartree-Fock multiplet energy of the ${}_{}{}^6{}_{}{}^{}P$ state is computed to be -2.2 eV. The effects of the energy dependence of the parameters entering the Fano formalism are examined and the strength of other transitions (e.g., $3p\to 4d$) is estimated. The importance of the interaction with continua of the form $3p^{5}3d^{m}4s^n\epsilon l$, $m+n=7\mathrm{}$, (the mechanism of Dehmer, Starace, Fano, Sugar, and Cooper) is assessed. The relationship of this work to calculations of the nonradiative lifetime of $3p$ holes in transition metals is discussed.