How Can We Get Roentgen Radiation ?
We've discussed only valency electrons so far which give optical spectrum. If the inner electrons are excited then we have a deal with Roentgen radiation from inner state. So far discussed constructive principle of periodical system takes into account the last outmost electron. If firstly electrons which are situated on the outmost shells are moving inside an atom then the effective potential of other electrons would change and level series of these intrinsic electrons are changing after that either. The energy consequence is then based upon the main quantum number n.

Fig.1: The rough structure of atomic energy levels and level series for the outmost electron and inner electrons. The most stable configuration is the following: the lower energy separation overlaps with one of more high levels.

Fig. 2: Roentgen transitions in an atom with atom number Z ~ 36. | Fig.3: Fine structure of Roentgen transitions.