[Wien] Effect of a finite nucleus on electron density at the nucleus

[Stefaan Cottenier]

> Clearly, for isomer shifts it might be that the problem is fixed by
> taking an appropriate alpha when converting into mm/s.

I share this opinion. The density at the first mesh point is probably 
quite 'wrong', but roughly by the same factor. And as isomer shifts are 
calibrated against a few experimental values rather than predicted in an 
absolute way, the conversion factor absorbs this problem to a large extent.

> In any case, the potential due to a finite nucleus would add another
> dimension.

Michael Filatov describes an alternative method to compute the isomer as 
an energy derivative, a procedure that is seamlessly consistent with a 
finite nucleus description: http://dx.doi.org/10.1016/j.ccr.2008.05.002 
  (Sec. 2.3, Coordination Chemistry Reviews 253 (2009) 594–605)

Stefaan