[Pw_forum] lattice parameter of Co

[Giuseppe Mattioli]

Dear vicky singh
I've done more than few calculations with that same Co pseudopotential.
Your wavefunction cutoff is far too low. I used 35/280 Ry. Which kind of cell 
optimisation have you performed? Have you tried vc-relax with bfgs? What 
about nspin=2? As you know, Co is a ferromagnetic metal...
However, your calculated parameters do not seem so bad to me.
Hope this help

Giuseppe

On Friday 17 December 2010 06:57:01 you wrote:
> Hi
> I am extremly sorry to attach wrong code for Co. Kindly ignore it. I am
> attaching the  correct code.
>
> vicky singh
>
> On Fri, Dec 17, 2010 at 11:09 AM, vicky singh 
<kirtinandan07 at gmail.com>wrote:
> > Hi
> > I am trying to determine the lattice parameter of hcp Co. The reported
> > experimental results is a = 4.74 bohr c/a = 1.62 but i am getting a =
> > 4.675 and c/a = 1.58 . I am using the GGA PP Co.pbe-nd-rrkjus.UPF which
> > is expected to overestimate the lattice parameter as compared to LDA PP
> > but here it is underestimating the lattice parameter by around 2%. am i
> > doing any thing wrong or this value i should proceed with this result for
> > my further calculation. I am attaching the input file and the plot of E
> > vs lattice parameter.
> >
> > Please help. Thanks in advance.
> >
> > vicky singh
> > research student
> > Bangalore



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   Giuseppe Mattioli                            
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