[Wien] Interstitial N-N pair in GaP supercell

[E.A.Moore]

If you want to study a pair of interstitial N atoms, you must add two N atoms, not replace P. Or if you are replacing P by two interstitial N atoms, you remove one P and add two N at new positions. 
Interstitial means the atoms are not on lattice sites. 
If the reduced cell has 16 inequivalent atoms, it sounds as  though you have 64 not 65 atoms, so possibly you have just replaced P by N on four sites. 

Are you trying to add an interstitial N2 molecule? If not why do you need two N atoms?

Elaine A. Moore

________________________________________
From: Kakhaber Jandieri [Kakhaber.Jandieri at physik.uni-marburg.de]
Sent: 04 July 2010 15:04
To: A Mailing list for WIEN2k users
Subject: Re: [Wien] Interstitial N-N pair in GaP supercell

Dear Swati,

Thank you for advice, but I still want to clarify some questions:

"first of all I think you can't replace one atom by a pair of atoms".

My final goal is to obtain the relaxed atom positions in GaP supercell
where one of the P atoms is replaced by the interstitial pair of
Nitrogen-Nitrogen atoms.
To say truth, I am not sure in correctness of my approach but I did the
following:
Step1 - Using the program "supercell" I generated 2x2x2 supercell for
GaP containing 64 atoms
Step2 -  I construct a new supercell with 64  inequivalent atoms using
the positions obtained in Step1
Step3 -  I split one P atom in 2 atoms
Step4 -  I changed the atoms obtained in Step3 from P to N
Step5 -  I ran "x sgroup". It converted my "p" supercell with 65
inequivalent atoms into the "111_p-42m" supercell with 16 inequivalent atoms
Step6 - I ran the program "mini".

Could you advice me the correct way for constructing the supercell with
interstitial pair of  N-N atoms in  GaP matrix?


"Set 5% less RMT for all types of atoms instead of reduction of RMT of N
only and run mini"

In interstitial N-N pair the interatomic distance between N atoms might be significantly smaller then the distance between Ga and P atoms.

If instead of 2.0 I take 5% less RMT, then how cam I prevent the overlapping of spheres between the N atoms in the interstitial pair?


Beforehand thankfull,
Kakha





swati chaudhury wrote:
> Hello,
>     first of all I think you can't replace one atom by a pair of atoms.
> Set 5% less RMT for all types of atoms instead of reduction of RMT of N only and run mini.
> best wishes.
> swati
>
> --- On Sun, 4/7/10, Kakhaber Jandieri <Kakhaber.Jandieri at physik.uni-marburg.de> wrote:
>
>
>> From: Kakhaber Jandieri <Kakhaber.Jandieri at physik.uni-marburg.de>
>> Subject: [Wien] Interstitial N-N pair in GaP supercell
>> To: wien at zeus.theochem.tuwien.ac.at
>> Date: Sunday, 4 July, 2010, 5:17 PM
>> In addition to my previous letter.
>>
>> I thought that may be the problem is in very large
>> difference between the RMT(Ga,P)=2.0 and RMT (N)=1.0, but I
>> cannot increase the RMT(N) because
>> of overlapping spheres and, on the other hand, I cannot
>> decrease the RMT(Ga,P) because of charge leakage.
>>
>>
>> Could somebody advice the solution of this problem?
>>
>> I will be extremely thankful for any suggestion.
>>
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>
>>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>
>

_______________________________________________
Wien mailing list
Wien at zeus.theochem.tuwien.ac.at
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien

-- 
The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England & Wales and a charity registered in Scotland (SC 038302).