Abstract
Multielectron calculations for the 3p photoabsorption cross section of free Mn+ (3p63d54s7S) are performed for the first time. The essential influence of a strong mixing between the 3p to 4s and giant 3p to 3d resonances on the 3p absorption cross section is discovered. Theoretical arguments that the available experimental data for the Mn+ 3p absorption spectrum could belong not to the 'pure' Mn+ absorption but to the mixed absorption of Mn+, excited Mn+* ion and neutral Mn atom are put forward.