The geometric phase γ Z (r cyl , z) in Eq. ( ) is pathdependent: when the radius or the nuclear charge go to zero, γ vanishes. In turn, at large distances, z → ∞ and/or r cyl → ∞, or for large nuclear charge, Z → ∞, γ approaches 2π [see Figs. . By virtue of Stokes' theorem, the value of γ Z (r cyl , z) corresponds to the flux of the effective magnetic field B = ∇ × A [Eq. and Fig. i.e. the curvature, through the surface bounded by C. Thus, it reaches an asymptotic value at large distances because then all flux is enclosed. Similarly, increasing the nuclear charge corresponds to concentrating all the flux at the origin leading to a path-independent value. The limit Z → ∞ is vaguely reminiscent of the M → ∞ limit of the nuclear mass(es) in the electronuclear problem when invoking the Born-Oppenheimer adiabatic approximation , typically π.