The ABINIT Users Mailing List ( CLOSED )

["Nuno A. G. Bandeira" <nuno.bandeira@ist.utl.pt>]

Xavier Gonze wrote:

> (2) More preoccupying, and independent of ABINIT : one cannot compute 
> straightforwardly
> the Vxc (and Kxc) corresponding to a meta-GGA like TPSS (one needs an 
> OEP method - quite unpleasant).
> So, I think that in the available implementations (Gaussian 03, WIEN), 
> the TPSS is computed
> in a one-shot calculation, on top of a LDA (or GGA) density, not 
> self-consistently.
> So, all optimizations have to be done without the gradients (so, without 
> the forces, and stresses).
> It is even worse for the computation of the interatomic force constants, 
> that one will not be able
> to do using the linear-response theory (or with an enormous 
> implementation effort)

This is not true for Gaussian. The latest revisions (C.02 onwards) have 
fully analytic frequencies and thermochemical data available for TPSS 
and TPSSh.
But as you say this is quite unusual in quantum chemistry programs. 
NWChem only has numerical gradients for all meta-GGAs namely VS98, TPSS, 
HCTH-tau. ADF only does single-points, and GAMESS and ORCA don't even 
have meta-GGAs.

I know this because I recently performed a calculation using the TPSS 
functional to compare with results from different functionals and 
noticed the gradient and hessian routines in Gaussian are fully 
analytic. Not surprisingly since prof. Gustavo Scuseria, one of the 
creators of the functional, is in the Gaussian development team...

I've never used Wien2k perhaps someone has some experience with this 
software ?


--
Nuno A. G. Bandeira, AMRSC
Graduate researcher and molecular sculptor
Inorganic and Theoretical Chemistry Group,
Faculty of Science
University of Lisbon - C8 building, Campo Grande,
1749-016 Lisbon,Portugal
http://cqb.fc.ul.pt/intheochem/nuno.html
Doctoral student @ IST,Lisbon
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