Re: [Pw_forum] Amorphous Solid

[Sarah Alpine]

Great, thanks very much Layla and Alan!

On Wed, Feb 24, 2016 at 1:43 PM, Alan J. R. Ambrozio 
wrote:

> Hi Sarah,
>
> You can do it using Lammps or Quantum Wise. Quantum Wise has this example
> using cristobalite. The tutorial is here
> http://quantumwise.com/publications/tutorials/item/845-generating-amorphous-structures
>
>
> You can try the trial license. ;)
>
> cheers
> Alan
>
> 2016-02-24 18:09 GMT-03:00 Sarah Alpine :
>
>> Thanks for your response, Layla. I don't know about this process; can you
>> please direct me to an example or some literature that would describe it in
>> detail? Is there QE code anywhere that I can reference?
>> Thanks!
>>
>> On Wed, Feb 24, 2016 at 12:23 PM, Layla Martin-Samos <
>> lmartinsa...@gmail.com> wrote:
>>
>>> Dear Sarah, you can also use a cristobalite supercell and make molecular
>>> dynamics at high temperature to obtain a liquid and then quench it.
>>>
>>> cheers
>>>
>>> Layla
>>>
>>> 2016-02-24 20:46 GMT+01:00 Sarah Alpine :
>>>
 Dear All,
  I am trying to simulate amorphous SiO2. If I am correct, it
 structures as tetrahedral arrangements wherein all the tetrahedra are
 connected, but have random orientations. So, what I am envisioning to do is
 create a supercell of about 20 tetrahedra, and orient these 20 based on a
 Monte Carlo method. Is this the correct way to simulate the amorphous SiO2?
 And if it is, are there any suggestions for how to use a Monte Carlo method
 to find the atomic positions?
 I'd appreciate any feed back.
 Thanks,
 Sarah

 ___
 Pw_forum mailing list
 Pw_forum@pwscf.org
 http://pwscf.org/mailman/listinfo/pw_forum

>>>
>>>
>>> ___
>>> Pw_forum mailing list
>>> Pw_forum@pwscf.org
>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>
>>
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum@pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
>
> --
> Alan J. R. Ambrozio
> Visitant PhD student
> Room E19-722
> Massachusetts Institute of Technology
> 857 316-8562
>
> ___
> Pw_forum mailing list
> Pw_forum@pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Amorphous Solid

[Alan J. R. Ambrozio]

Hi Sarah,

You can do it using Lammps or Quantum Wise. Quantum Wise has this example
using cristobalite. The tutorial is here
http://quantumwise.com/publications/tutorials/item/845-generating-amorphous-structures


You can try the trial license. ;)

cheers
Alan

2016-02-24 18:09 GMT-03:00 Sarah Alpine :

> Thanks for your response, Layla. I don't know about this process; can you
> please direct me to an example or some literature that would describe it in
> detail? Is there QE code anywhere that I can reference?
> Thanks!
>
> On Wed, Feb 24, 2016 at 12:23 PM, Layla Martin-Samos <
> lmartinsa...@gmail.com> wrote:
>
>> Dear Sarah, you can also use a cristobalite supercell and make molecular
>> dynamics at high temperature to obtain a liquid and then quench it.
>>
>> cheers
>>
>> Layla
>>
>> 2016-02-24 20:46 GMT+01:00 Sarah Alpine :
>>
>>> Dear All,
>>>  I am trying to simulate amorphous SiO2. If I am correct, it
>>> structures as tetrahedral arrangements wherein all the tetrahedra are
>>> connected, but have random orientations. So, what I am envisioning to do is
>>> create a supercell of about 20 tetrahedra, and orient these 20 based on a
>>> Monte Carlo method. Is this the correct way to simulate the amorphous SiO2?
>>> And if it is, are there any suggestions for how to use a Monte Carlo method
>>> to find the atomic positions?
>>> I'd appreciate any feed back.
>>> Thanks,
>>> Sarah
>>>
>>> ___
>>> Pw_forum mailing list
>>> Pw_forum@pwscf.org
>>> http://pwscf.org/mailman/listinfo/pw_forum
>>>
>>
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum@pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
> ___
> Pw_forum mailing list
> Pw_forum@pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
Alan J. R. Ambrozio
Visitant PhD student
Room E19-722
Massachusetts Institute of Technology
857 316-8562
___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum

[Pw_forum] R: Amorphous Solid

[layla martin]

Search for old walter kob papers, or old alfredo pasquarello papers.

Cheers

Layla

- Messaggio originale -
Da: "Sarah Alpine" 
Inviato: ‎24/‎02/‎2016 22:10
A: "PWSCF Forum" 
Oggetto: Re: [Pw_forum] Amorphous Solid

Thanks for your response, Layla. I don't know about this process; can you 
please direct me to an example or some literature that would describe it in 
detail? Is there QE code anywhere that I can reference?

Thanks!



On Wed, Feb 24, 2016 at 12:23 PM, Layla Martin-Samos  
wrote:

Dear Sarah, you can also use a cristobalite supercell and make molecular 
dynamics at high temperature to obtain a liquid and then quench it.


cheers


Layla


2016-02-24 20:46 GMT+01:00 Sarah Alpine :

Dear All,

 I am trying to simulate amorphous SiO2. If I am correct, it structures as 
tetrahedral arrangements wherein all the tetrahedra are connected, but have 
random orientations. So, what I am envisioning to do is create a supercell of 
about 20 tetrahedra, and orient these 20 based on a Monte Carlo method. Is this 
the correct way to simulate the amorphous SiO2? And if it is, are there any 
suggestions for how to use a Monte Carlo method to find the atomic positions?

I'd appreciate any feed back.

Thanks,

Sarah



___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum




___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Amorphous Solid

[Sarah Alpine]

Thanks for your response, Layla. I don't know about this process; can you
please direct me to an example or some literature that would describe it in
detail? Is there QE code anywhere that I can reference?
Thanks!

On Wed, Feb 24, 2016 at 12:23 PM, Layla Martin-Samos  wrote:

> Dear Sarah, you can also use a cristobalite supercell and make molecular
> dynamics at high temperature to obtain a liquid and then quench it.
>
> cheers
>
> Layla
>
> 2016-02-24 20:46 GMT+01:00 Sarah Alpine :
>
>> Dear All,
>>  I am trying to simulate amorphous SiO2. If I am correct, it
>> structures as tetrahedral arrangements wherein all the tetrahedra are
>> connected, but have random orientations. So, what I am envisioning to do is
>> create a supercell of about 20 tetrahedra, and orient these 20 based on a
>> Monte Carlo method. Is this the correct way to simulate the amorphous SiO2?
>> And if it is, are there any suggestions for how to use a Monte Carlo method
>> to find the atomic positions?
>> I'd appreciate any feed back.
>> Thanks,
>> Sarah
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum@pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
> ___
> Pw_forum mailing list
> Pw_forum@pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum

Re: [Pw_forum] Amorphous Solid

[Layla Martin-Samos]

Dear Sarah, you can also use a cristobalite supercell and make molecular
dynamics at high temperature to obtain a liquid and then quench it.

cheers

Layla

2016-02-24 20:46 GMT+01:00 Sarah Alpine :

> Dear All,
>  I am trying to simulate amorphous SiO2. If I am correct, it
> structures as tetrahedral arrangements wherein all the tetrahedra are
> connected, but have random orientations. So, what I am envisioning to do is
> create a supercell of about 20 tetrahedra, and orient these 20 based on a
> Monte Carlo method. Is this the correct way to simulate the amorphous SiO2?
> And if it is, are there any suggestions for how to use a Monte Carlo method
> to find the atomic positions?
> I'd appreciate any feed back.
> Thanks,
> Sarah
>
> ___
> Pw_forum mailing list
> Pw_forum@pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum

[Pw_forum] Amorphous Solid

[Sarah Alpine]

Dear All,
 I am trying to simulate amorphous SiO2. If I am correct, it structures
as tetrahedral arrangements wherein all the tetrahedra are connected, but
have random orientations. So, what I am envisioning to do is create a
supercell of about 20 tetrahedra, and orient these 20 based on a Monte
Carlo method. Is this the correct way to simulate the amorphous SiO2? And
if it is, are there any suggestions for how to use a Monte Carlo method to
find the atomic positions?
I'd appreciate any feed back.
Thanks,
Sarah
___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum

[Pw_forum] Possible bug in TB09 MetaGGA

[Pedro Miguel Castro Borlido]

Greetings,

I understand that the implementation of the TB09 meta gga is done  
in Espresso
though Libxc, as described in the article by Germaneau and colleagues.
However, while looking through the code it seems that at no point  
the c parameter
(equation 3 of PRL 102, 226401 (2009)) is set with  
xc_f90_mgga_x_tb09_set_par thus
leaving c equal to 1 by default (i.e. the original BJ is used).

   Could someone please check if this is actually a bug of if c is  
actually set?

Best regards,
Pedro Borlido

Friedrich-Schiller Universität Jena
Institut für Festkörpertheorie und -optik
Max-Wien-Platz 1
07743 Jena


___
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum