[CPMD-list] Na PP

[Juerg Hutter]

Hi

To do reasonable simulations with free Na atoms you need
either a semi core (only 1s electrons in the core) or a
NLCC (non-linear core corection) pseudopotential.
As stated in the JACS paper you reference, we used a
semi-core pp of GTH type (see 
http://cvs.berlios.de/cgi-bin/viewcvs.cgi/cp2k/potentials/Goedecker/cpmd/
for a full list of available PP; Na-q9 is the one used in the paper).
The cutoff of 70 Ry will not give fully converged results for
all propoerties but was good enough (only a reasonable description
of the 2s2p states is needed) for the special project.

regards

Juerg Hutter


----------------------------------------------------------
Juerg Hutter                   Phone : ++41 44 635 4491
Physical Chemistry Institute   FAX   : ++41 44 635 6838
University of Zurich           E-mail: hutter at pci.uzh.ch
Winterthurerstrasse 190
CH-8057 Zurich, Switzerland
----------------------------------------------------------


On Sun, 11 May 2008, Jiten wrote:

> Thanks Axel for the reply.
>
> There are two PP available in the pplib directory Na_MT_NLCC.psp
> Na_SEMI_BLYP.psp presumably could be used with the BLYP (both are
> nornconserving types). As there is no ref in the PP info, I wonder which one
> is used in the J. Am. Chem. Soc. 2000, 122, 4837-4838 article.
>
> It will be really nice if Hutter could give an advice in this regard.
>
> Sincerely,
>
> Jiten
> ----- Original Message -----
> From: "Axel Kohlmeyer" <akohlmey at cmm.chem.upenn.edu>
> To: "Jiten" <jiten at postech.ac.kr>
> Cc: <cpmd-list at cpmd.org>
> Sent: Saturday, May 10, 2008 7:04 PM
> Subject: Re: [CPMD-list] Na PP
>
>
>> On Sat, 10 May 2008, Jiten wrote:
>>
>> JS> Dear CPMD users,
>>
>> dear jiten,
>>
>> JS> In J. Am. Chem. Soc. 2000, 122, 4837-4838 (Christopher J. Mundy,
>> JS> Ju¨rg Hutter, and Michele Parrinello) abou the Na-water clusters, it
>> JS> says that
>>
>> JS>
>> JS> "Norm-preserving pseudopotentials were used to describe the oxygen,
>> JS> hydrogen, and sodium cores. In the case of Na, the 2s2-2p6-3s1
>> JS> electrons were included explicitly."
>> JS>
>>
>> JS> I am just wondering if I need to do anything with the Na PP
>> JS> (Na_SEMI_BLYP.psp) for this purpose.
>>
>> i don't quite understand the question. which electrons are put into
>> valence or not is decided when constructing the pseudo-potential and
>> you cannot change it. the label "semi" indicates that the potential
>> in question does meet the same requirements as the one in the paper.
>>
>> the only options that you can vary are the choice of local potential
>> and the cutoff. and from looking at similar potentials, i would suspect
>> that i will be a "hard" potential and that it is quite possible
>> the default LOCAL=P will give you ghost states...
>>
>> cheers,
>>    axel.
>>
>> JS>
>> JS> Any comment is appreciated.
>> JS>
>> JS> Sincerely,
>> JS>
>> JS> N. Jiten Singh
>> JS> C/O Prof. Kwang S. Kim
>> JS> Department of Chemistry
>> JS> Pohang University of Science and Technology
>> JS> San 31, Hyojadong, Namgu
>> JS> Pohang 790-784, Korea
>> JS> Phone : 82-54-279-5853 ( Lab ) / 279-4138 ( Appt )
>> JS> Fax : 82-54-279-8137 (or +82-54-279-3399)
>> JS> Web : http://csm.postech.ac.kr/ and http://www.postech.ac.kr/e
>> JS> Home Page : http://www.geocities.com/njs_19
>>
>> --
>> =======================================================================
>> Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
>>   Center for Molecular Modeling   --   University of Pennsylvania
>> Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
>> tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
>> =======================================================================
>> If you make something idiot-proof, the universe creates a better idiot.
>
>
>
>
>
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