Re: CCL:G:G94: B3LYP energy and Charge

[frisch (+ at +) lorentzian.com (Mike Frisch)]

 Ross Nobes writes:
 >
 > Ulf Ryde writes:
 >   >
 >   > I have just started to use Gaussian, and I have noted two strange
 things
 >   > with G94: (I sent this question to info (+ at +) gaussian.com two
 weeks ago, but
 >   > I have got no answer)
 >   >
 >   > 1. Gaussian does not give the same B3LYP energy as IBM:s Mulliken.
 >   >    Who is right?
 >
 > The answer is that both are right!  The Gaussian definition of B3LYP
 > uses the VWN local correlation functional;  most other programs use
 > what Gaussian terms VWN5.
 >
 No, B3LYP was defined to use VWN3.  Using the same name for two different
 functionals is a disservice to everyone and makes reproducing other peoples
 results impossible.  This used to be a major problem in the DFT area, and
 things are finally improving with regard to terminology.  To take a name for
 something that is specified in the literature and use it for something
 different is a major step backwards.  Published and in-press tests of B3LYP
 all use VWN3; an assumption that the same conclusions apply to a different
 functional just because it has the same name are not valid.
 Mike Frisch
 frisch (+ at +) lorentzian.com