Subject: KMLYP in Gaussian 98 and G03

From: "Joseph Han" <josephh(at)stanford.edu>
Date: Tue, 2 Dec 2003 11:02:52 -0800

Dear CCL Community,

I wanted to bring to your attention some changes in the implementation
for general hybrid functionals in Gaussian 03 as compared to Gaussian
98.  Specifically, this affects the input required for using KMLYP, a
method developed here at Stanford University.

For G98, the old input used to be "iop(5/45=10000557) iop(5/46=00000443)
iop(5/47=04481000)".  

However, for G03, not only have the overlay numbers changed, but so has
the number of significant figures.  The new input should be
"iop(3/76=1000005570) iop(3/77=0000004430) iop(3/78=0448010000)"  

A note of caution, when using IOP's to specify KMLYP, do not perform a
combined "freq opt" calculation.  If you do, the frequency calculations
will be performed using another method instead of KMLYP.  Opt=(calcfc),
opt=(calcall), and using checkpoint files are all OK with KMLYP.

Thanks go to Jim Hess at Gaussian for his help is explaining the changes
between G98 and G03.

Joseph Han
Department of Chemical Engineering
Stanford University
650-723-0420
FAX:  650-725-7294