[Wien] Reconstructed Si 100 surface

[Muhammad Sajjad]

Thank you very much Fecher and Michael.

On Mon, Jul 27, 2015 at 12:11 PM, Michael Sluydts <michael.sluydts at ugent.be>
wrote:

>  It is recommended to make both your slab surfaces identical where
> possible. The p21, p22 and p24 refer to the type of supercell used to
> represent the surface. Since you are using a periodic model you are
> imposing a strong symmetry on the surface, not all reconstructions can be
> made within your unit cell, indeed for your dimer you will need a 2x1
> expansion, i.e. two cells next to eachother along the a axis. The symbols
> (and possible angles) represent the shape and rotation of the resulting
> cell (in this case p=primitive, c=centered).
>
> You can find more info in for instance:
> Introduction to Solid State Physics - Kittel - about the description of
> cells
> and
> Density Functional Theory: A Practical Introduction - Sholl and Steckel  -
> for the basics of how to model surfaces
>
> Muhammad Sajjad schreef op 27/07/2015 om 10:51:
>
>   Dear Delamora and Michael
>  Many thanks for informative suggestions.
>   I am intended to study electronic properties of Si (100) of thickness 1
> nm. I am asked to introduce dimers instead of using H. But my question is
> "one surface of the Si 100 must be passivated by hydrogen or not?"Like If
> ones introduce dimer on the top (maximum Z) then bottom (minimum Z) must be
> passivated or not? Can we introduce dimers on both surfaces (top & bottom).
> I am reading the paper ( http://pubs.acs.org/doi/pdf/10.1021/jp509095t ).
> What does it means P21, P22, P24 reconstructions?
>
>  Many thanks
>
>
> On Sun, Jul 26, 2015 at 10:51 PM, Michael Sluydts <
> michael.sluydts at ugent.be> wrote:
>
>>  Muhammad,
>>
>> When you move the two Si atoms with the dangling bond towards eachother
>> you will create a dimer on the surface, no extra passivation by H atoms is
>> needed, just ensure you make your slab symmetric where possible. If you
>> google Si recontructions you should find very exact geometrical information
>> since this has been done many times before.
>>
>> Best regards,
>>
>> Michael Sluydts
>>
>> Muhammad Sajjad schreef op 26/07/2015 om 17:59:
>>
>>  Thank you Pablo
>>  But I am required to connect two Si atoms at the surface to reduce one
>> dangling bond and then put H or may be H is not needed if both of the
>> dangling bonds have possibility of omitting. I am reading the paper but
>> could not understand although Fig. 2 is looking easy to understand. WHat is
>> 2*1 or 2*2 or 2*4 ? are the super-cells like 2*1*1 or 2*2*1 etc.
>>
>>
>> On Sun, Jul 26, 2015 at 6:22 PM, delamora <delamora at unam.mx> wrote:
>>
>>>  This is the same that I simplified and symmetized. If you are going to
>>> add H then you need set the space group as P1 (#1) so the H can move freely
>>> and not in a symmetrical path.
>>>
>>> Now, if you use my proposed structure then you can put inversion (SG
>>> P-1, #2) and add two H, one on each surface, but in a symmetric way.
>>>
>>> Other thing, maybe my proposed structure is too small and your structure
>>> is ok, but I would symmetrize as I explained in an earlier message.
>>>
>>>                        Pablo
>>>  ------------------------------
>>> *De:* wien-bounces at zeus.theochem.tuwien.ac.at <
>>> wien-bounces at zeus.theochem.tuwien.ac.at> en nombre de Muhammad Sajjad <
>>> sajjadpu at gmail.com>
>>> *Enviado:* domingo, 26 de julio de 2015 04:44 a. m.
>>> *Para:* wien
>>> *Asunto:* [Wien] Reconstructed Si 100 surface
>>>
>>>    Dear Users
>>>  Kindly guide me how to reconstruct Si 100 layer? The Si 100 structure
>>> is attached here with. It has two dangling bonds on both surfaces (Top and
>>> Bottom). My intension is to keep one dangling bond on the top and bottom
>>> surfaces that will be saturated by H addition.
>>>  --
>>>  Kind Regards
>>> Muhammad Sajjad
>>> Post Doctoral Fellow
>>> KAUST, KSA.
>>>
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>>>
>>>
>>
>>
>> --
>>  Kind Regards
>> Muhammad Sajjad
>> Post Doctoral Fellow
>> KAUST, KSA.
>>
>>
>> _______________________________________________
>> Wien mailing listWien at zeus.theochem.tuwien.ac.athttp://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
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>>
>>
>>
>>   --
>> ir. Michael Sluydts
>> Center for Molecular Modeling
>> Ghent University
>> Technologiepark 903
>> 9052 Zwijnaarde, Belgium
>> tel. +32 (0)9 264 66 19https://molmod.ugent.be
>>
>>
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>>
>
>
> --
>  Kind Regards
> Muhammad Sajjad
> Post Doctoral Fellow
> KAUST, KSA.
>
>
> _______________________________________________
> Wien mailing listWien at zeus.theochem.tuwien.ac.athttp://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
>
>
> --
> ir. Michael Sluydts
> Center for Molecular Modeling
> Ghent University
> Technologiepark 903
> 9052 Zwijnaarde, Belgium
> tel. +32 (0)9 264 66 19https://molmod.ugent.be
>
>
> _______________________________________________
> Wien mailing list
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> SEARCH the MAILING-LIST at:
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>
>


-- 
Kind Regards
Muhammad Sajjad
Post Doctoral Fellow
KAUST, KSA.
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