CCL: W:How can I modify the van der waals radii of elements in Gaussian 03?

From: "Adrian Villegas" <adriano{:}eps.mcgill.ca>
Subject: CCL: W:How can I modify the van der waals radii of elements in Gaussian 03?

 Sent to CCL by: "Adrian  Villegas" <adriano{:}eps.mcgill.ca>
 To: CCL subscribers
 > From: Adrin Villegas
 Hey folks,
 I want to use the CHelpG function in Gaussian 03 in order to calculate
 the molecular electrostatic potential of a crystal containing calcium
 and derive the corresponding atomic charges.
 Unfortunately, the value of the van der waals (vdw) radius for calcium is
 not specified in the Gaussian database and, thus, the program crashes before the
 calculation can be completed.
 Any idea about how to specify/enter the vdw radius of this element in the
 Gaussian 03 database? (I want to test my calculation using an approximate vdw
 value for calcium since I could not find the actual value in any major handbook
 or database containig physical constants/values).
 Any piece of information would be greatly appreciated!
 Adrin