A detailed analysis of the x-ray spectrum emitted by laser-produced plasma of samarium (6–12 Å) is presented, using ab initio calculations with the HULLAC relativistic code and isoelectronic considerations. Resonance $3d\text{-}nf$ ( $n=4$ to 7), $3p\text{–}4d$ , $3d\text{–}4p$ , and $3p\text{–}4s$ transitions in Ni samarium ions and in neighboring ionization states (from Mn to Zn ions) were identified. The experiment results show changes in the fine details of the plasma spectrum for different laser intensities.