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["Shultz, Jack" <JShultz@nas.edu>]

Nicola,

I looked at some of the research described on your website. Is the
Hubbard approach to augment DFT the same thing as DFT+U? I'm also trying
to find out what is meant by a nodal surface is that how you describe
the environment of an enzyme?

Jack

-----Original Message-----
From: Nicola Marzari [mailto:marzari@mit.edu] 
Sent: Wednesday, December 19, 2007 10:38 AM
To: forum@abinit.org
Subject: Re: [abinit-forum] Predicting TSS



Dear Jack,

the molecular catalysts that do water splitting are transition-metal
complexes that are not described correctly by most approximations to
DFT. QMC does not help that much, if you start from a nodal surface that
is qualitatively wrong. We believe in DFT+U approaches (and have 
published recently on the matter), but there is no point in data
mining structures and energetics that have barriers in error by
more than 1eV. The problem is more on self-interaction than weak
van-der-Waals.


                                nicola


Shultz, Jack wrote:
> Thank you Nichols. I will need to do more reading. I often find myself

> getting lost when trying to understand quantum simulations. I lack
much 
> of the vocabulary or sufficient background knowledge to understand
most 
> of the literature I find. But your explanation seems simple. I am also

> trying to get in touch with the developers of QMC@Home to get an idea
on 
> implementing QMC for my project.
> 
>  
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Prof Nicola Marzari   Department of Materials Science and Engineering
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