What are the common atomic radii used for chemical pictures?

[somasimple]

Hi all,

What are the common atomic radii that are used for drawing chemical pictures?

Is it the ionic or calculated or?

Thanks.

 

[Borek]

Whatever, as far as I am aware there are no set rules. There is some obvious logic that you can apply, but as long as your pictures are not drawn to be a scientific tool (like DNA models built by Watson and Crick) you don't have to pay too much attention to it. Just be consistent.

 

[alxm]

My program uses (for its default ball-and-stick mode) half the covalent radii. (vdW radii look a bit too chunky). Most programs use something similar. (To the extent I sometimes see papers with images that might have been made with my program, but I can't be sure) "Spacefill" models would be around the full covalent radius, or slightly larger.

It's not like the spheres in these pictures have much in the way of physical meaning; you're only drawing the structure.
If you want to say something about orbitals or bonding or electron densities, then that's what you plot, not ball-and-stick models.