Nonbonded radius in AIM theory

[Reinaldo Pis Diez <pis_diez <> yahoo.com.ar>]

 	Dear ccl'ers,
		We're using the AIMPAC set of programs to study some systems having
 hydrogen bonds. To this end, we apply some criteria suggested several
 years ago by Koch and Popelier (J Phys Chem 99 (1995) 9747-9754).
 However, we are a little confused about the calculation of nonbonded
 radii. A nonbonded radius is defined in the above reference as
 "the
 distance of a nucleus to a given charge density contour in the
 monomer...[edited] usually taken as 0.001 au".
 		My question is: How can I obtained nonbonded radii  for those atoms
 involved in a hydrogen bond? Which AIMPAC program do  I have to use to?
 		Thanks in advance.
 		Regards,
 						Reinaldo