[PyMOL] Radii in Angstrom

[<tan...@st...>]

Hi,

if I show up a sphere around an picked atom, and want to change its radius, I
always use the
  set sphere_scale
method. But, to which value am I scaling to? Isn't it possible to change the
radius of a sphere with something like 'set sphere_radius' in Angstroms?
I could not find any information in the manual and the reference.
My aim is to project a sphere (or another projection) with a certain radius like
3.2 Angstrom around an atom. After I realized that I could not do this with the
implemented spheres, I checked the
  set dots_* methods,
where I did find a
  set dots_radius.
But everytime I use this function, the dots stay at their position and PyMol
does not change anything on screen (and raytracing leeds to a crash).

So, am I doing anything wrong or are these methods not available at the moment?

Regards

Yusuf Tanrikulu