Large component hydrogenic radial function

Figure 6.1 Radial functions Pis (r) and Qij (r), in Hartree atomic units, of the ground state Dirac spinor of the hydrogen-like atoms with Z = 40,80,130, i.e., for Zr +, Hg +, and 130i +, With increasing nuclear charge the radial functions contract. The small component Qis (r) is small indeed for not too large nuclear charges, but its overall size increases with Z in such a way that Plsir) and Qis (r) are of similar size (but different sign) for Z = 130, i.e., if Z c in atomic units.

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