Hi!

For example, there is article - Consistent van der Waals Radii for the Whole Main Group, Manjeera Mantina, Adam C. Chamberlin, Rosendo Valero, Christopher J. Cramer, and Donald G. Truhlar, J. Phys. Chem. A 2009, 113, 19, 5806-5812. https://doi.org/10.1021/jp8111556

More methods are described in the introduction to the article.

Roman G. Fedunov Thank you

According to the Bader's definition, vdW radius can be defined as distance between nucleus and a point on the isosurface of rho=0.001. Based on this definition, you can use Multiwfn (http://sobereva.com/multiwfn) to calculate atomic radius easily.

As an example, we calculate radius for Ar, the needed wavefunction file has already been provided in Multiwfn package. Boot up Multiwfn and input below commands

examples\atomwfn\Ar.wfn

12

6

10

1

You will see:

The farthest distance to the point: 3.735141 Bohr ( 1.976552 Angstrom)

That means the vdW radius can be regarded as 1.976 Angstrom.

For silver and its ion, you can use such as Gaussian to generate .fch/wfn/wfx file, which can be used as input file for above analysis to derive their radii.