Re: CCL:fractional nuclear charge

 Hello Steve and All!
 On Wed, 5 Nov 2003, Steve Williams wrote:
 > I have a colleague who would like to some quantum chemistry calculations on
 > the following system: R-OH+  --> R-NH, that is, a smooth transition from
 > open shell alcohol radical cation to a neutral radical amide.  Is there a
 > way to do this?  We discussed several options, based on what we have here:
 > 3) Is there existing code out there that already does this?
 With Turbomole ( you can do this. Or, I should
 say, you can at least define a fractional nuclear charge, and Turbomole
 performs the calculation. I tried HF, DFT and RI-MP2 on N2 with one of
 the N's having a q of +6.5.
 The basis set might be a problem, as they are optimised for specific
 atoms. I guess one way of getting around this would be to use a combined
 basis set for the metamorphosing atom, consisting of the BS of both
 the initial (O) and the final (N) atoms.
 Have a nice day,
     Mikael Johansson
     University of Helsinki
     Department of Chemistry
     Phone: +358-9-191 50185
     FAX  : +358-9-191 50169