[CPMD-list] Getting lattice constant of Pt bulk

[Ari P Seitsonen]

Dear Hong Won Keon,

   You MUST use k points when doing calculations for the lattices (i.e. for 
periodic systems), unless you do have large enough cell. However for 
metals this would mean hundreds of atoms, so it's better to use the 
minimal cell and (a lot of) k points.

   Please see also the keyword 'TESR' and use it.

     Greetings from Paris / IMPMC,

        apsi

On Wed, 30 Mar 2005, Hong Won Keon wrote:

> Hi, CPMD-lists,
>
>
>
> I'm in trouble with getting lattice constant of Pt bulk.
>
> I've tried many ways to do so, but still struggling.
>
>
>
> I chose 3 PP - Goedecker PP, US PW91 PP which are available in CPMD and
> website and TM PW91 which I generate using fhi98PP.
>
>
>
> To get equilibrium lattice constant, I did first, run "single point
> calculation - Wavefunction Optimization" then do "murnaghan fitting"
> with murn.x that was downloaded in fhi website. However, I cannot get
> good lattice constant which should be close to 3.92~4.0 A.
>
> Some say my calculation may be wrong. So I attach my input files for
> each PPs. Please give me some advice.
>
>
>
> For TM PW91, I'm struggling to find out good PPs. To find out good PP, I
> check the PP with lattice constant. But still too far.
>
>
>
>
>
> Please help me!
>
>
>
> Thanks,
>
>
>
> Hong won keon
>
>
>
>

-- 
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   Ari P Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
   CNRS & IMPMC, Université Pierre et Marie Curie
       4 place Jussieu, case 115 / F-75252 Paris
   Tel: +33-1-4427 7542, Fax: +33-1-4427 3785, GSM: +33-6-6736 3820