[Pw_forum] Pseudopotential combination

[Axel Kohlmeyer]

On Sat, May 17, 2014 at 9:56 AM, Elliot Menkah <elliotsmenkah at yahoo.com>wrote:

>  Hello Everyone,
>
> I'm making an adsorption study of carbon monoxide(CO) on pure nickel(Ni)
> surfaces.
> I use the pseudopotential Ni.pbe-nd-rrkjus.UPF to optimized the pure
> nickel system.
> Is it wrong to use C.pbe-van_ak.UPF for carbon and  O.pbe-van_ak.UPF for
> the oxygen rather than using C.pbe-rrkjus.UPF and O.pbe-rrkjus.UPF
>

​no.​


> When I use the *pbe-van_ak.UPF* to optimize the CO separately, I get an
> energy of *-75.5429425135* Ry whereas *pbe-rrkjus.UPF* gives me an energy
> of *-75.1901795049* Ry.
>

​absolute energies have no meaning in pseudopotential calculations.


>
> In consideration of the energetics and stability, I want to go in for the
> pbe-van_ak.UPF for the system of CO on Ni surface. Is it wrong please?
>

​no.​



>
>
> Kind Regards,
>
> Elliot
>
> --
> Elliot Sarpong Menkah
> Graduate Student - Computational Chemistry / Computational Material Science.
> Theoretical and Computational Chemistry
> Dept. of Chemistry
> Kwame Nkrumah University of Science and Technology (KNUST),
> Private Mail Bag,
> Kumasi,
> Ghana.
> Mobile:+233-243-055-717,+233-202-929-058
>
>
> Alt. Email: elliotsmenkah at gmail.com
>                 elliotsmenkah at hotmail.com
>
> webpage: http://archive.knust.edu.gh/pages/sections.php?siteid=chemistry&mid=806&sid=2754
>
>
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-- 
Dr. Axel Kohlmeyer  akohlmey at gmail.com  http://goo.gl/1wk0
College of Science & Technology, Temple University, Philadelphia PA, USA
International Centre for Theoretical Physics, Trieste. Italy.
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