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[Vincenzo Fiorentini <vincenzo.fiorentini@dsf.unica.it>]

I suppose that in LaTiO3 (as in other lanthanide oxides) one can get  
away without the unoccupied La 4f. Since the main playground of U is  
on Ti d (the Mott gap is due to Ti being 3+ in lantanide titanates),  
one may simply not apply it to La f's.

Vincenzo Fiorentini


On 13 Feb 2008, at 5:32 PM, bernard amadon wrote:

> Dear Joe,
>
> In fact, Abinit should give an error message instead of a crash.  
> The problem is only that LDA+U in PAW need projectors
> for the angular momentum on which the Hubbard correction is  
> applied. In other words, it it necessary physically to define the  
> atomic
> wavefunction used to compute the occupations and the Hubbard  
> correction.
> I am thus surprised by the fact that the authors  are able to
> use LDA+U on 4f states of La without including 4f states in the  
> atomic data...
> You could construct new atomic data with 4f states in it to see if  
> you recover their results.
>
> Best
> Bernard
>
> jzwanzig@dal.ca a écrit :
> > Dear Colleagues,
> > I have been running calculations using PAW together with LDA+U  
> > with some success, on various transition metal oxides. Recently  
> > I've looked at LaTiO3, and in a paper by Okatov, Poteryaev, and  
> > Lichtenstein, Europhys. Lett 70, 499 (2005), this compound is  
> > treated using GGA+U on both the Ti 3d and La 4f states. What  
> > puzzles me is that their PAW data set as described in the paper,  
> > doesn't have 4f states in it. In abinit, when I use a La PAW set  
> > based on 5s and 6s, 5p and 6p, and 5d, similar to what they  
> > describe, abinit crashes if I turn on lpawu for the La 4f  
> > electrons. I assume that that happens because I don't have 4f  
> > states in the PAW set to start with. So either I am doing  
> > something completely wrong with abinit, or the code the other  
> > authors use works differently that abinit does. Can someone  
> > clarify this for me?
> >
> > thanks,
> > Joe