[Wien] about the LDA+U

[Yushan Wang]

but, I really find the results obtained by LDA+U are different from those
by LDA only, although this system has a balanced spin-up and spin-dn
structure.

yushan

On Tue, 2 Nov 2004, jan kunes wrote:

> Dear yushan,
>
>
> > Dear users,
> > does the LDA+U apply to the light transition metal. such as Ti, V, Cr and
> > so on?
>
> It depends on the compound. It should work reasonably in systems, where
> the d electrons are localized, e.g. oxides.
>
> , and if the spin-up and spin-dn balance well, is the LDA+U
> > full of physical significance?
>
> No, LDA+U applies to ordered phase. If you have local moments as is
> typical for localized electrons, LDA+U provides a reasonable description
> of the ordered phase below T_c. Above T_c you still have local moments LM
> (Curie-Weiss susceptibility), but the fluctuate in time, i.e. this is not
> a non-magnetic NM state described by LDA or LDA+U. If you look at the
> occupation numbers <n> there is no difference between LM and NM, in
> both cases up=dn. The difference will be obvious from <N_up N_dn>. In NM
> <n_up n_dn>=<n_up><n_dn> while in LM <n_up n_dn> << <n_up n_dn> due to
> Coulomb repulsion (LDA+U however can not capture this behavior since it is
> static method).
>
> Jan
>
>
>  > > yushan
> >
> > _______________________________________________
> > Wien mailing list
> > Wien at zeus.theochem.tuwien.ac.at
> > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> >
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>