Re: [Phonopy-users] Kappa for 2D monolayer

[Altaf Ur R. <alt...@un...>]

Dear Atsushi Togo,
                  Thanks a lot for giving me time and answering.
yes Sir thermal conductivity should not be like W/m-K. But there are 
some model for 2D thickness.
I  am not familiar about  almabte but i see some paper, people are using 
ShenBTE for 2D graphene and bilayer (PHYSICAL REVIEW B 95, 085435 
(2017)). but again they says nothing about long range coulomb 
interaction in doing force calculation but just mention the vacuum in 
doing PW calculation. Ok I will check the almabte may be they use some 
method for coulomb truncation to avoid the interaction.

   thanks

Best Regards
   Altaf Ur Rahman
   PhD Research student
   Department of Physics
   University of Duisburg-Essen, Germany,


On 24.12.2017 09:08, Atsushi Togo wrote:
> Coulomb interaction can be long ranged. So I don't want to discuss.
> But you may have techniques to effectively avoid it and it needs
> detailed discussions, for which I am not a specialist. Of course the
> long range interaction results in its force constants. But if you
> assume you can ignore it, then you may run phono3py in the same way.
> However you have to carefully define the thermal conductivity measure,
> which should not be like W/m-K. In addition, this is technical point
> in phono3py calculation, you need very dense mesh because in 2D
> Brillouin zone, the phonon collision becomes more rare than that in
> 3D. All of these, I guess almaBTE people are better,
> http://www.almabte.eu/ than phono3py (am I correct?)
> 
> Togo
> 
> On Fri, Dec 22, 2017 at 5:44 PM, Altaf Ur Rahman
> <alt...@un...> wrote:
>> Dear Atsushi Togo, thanks a lot for giving me time.
>> 
>> I am thinking that if we take large vacuum it will be works fine for 
>> 2D or
>> not? because in PW calculation when we take a large vacuum in the
>> z-direction, then the Coulomb  interaction is supposed to be ignored. 
>> but i
>> do not know after completing the pw calculation after that there is 
>> some
>> rule of coulomb interaction in doing the force calculation or not, 
>> using
>> phono3py if some one knows pleas answer.
>> 
>>  thanks
>>  Best Regards
>> 
>>  Altaf Ur Rahman
>>  PhD Research student
>>  Department of Physics
>>  University of Duisburg-Essen, Germany
>> 
>> 
>> On 22.12.2017 01:05, Atsushi Togo wrote:
>>> 
>>> Hi,
>>> 
>>> Phonopy and phono3py assume 3D periodic boundary condition. It's not
>>> possible to ignore one of 3D though you may ignore it approximately 
>>> by
>>> employing some model. But I am not sure what model can be accepted in
>>> the 2D thermal conductivity calculation community, that is a kind of
>>> politics and I am unfortunately not a politician.
>>> 
>>> Togo
>>> 
>>> On Thu, Dec 21, 2017 at 10:32 PM, Altaf Ur Rahman
>>> <alt...@un...> wrote:
>>>> 
>>>> Hi every body, and happy new Year 2018 in advance,
>>>> 
>>>> I am new to phonopy and phono3py, i want to know about lattice 
>>>> thermal
>>>> conductivity, my question is that how to calculate lattice thermal
>>>> conductivity for 2D mono layer, there is some special method for 2D 
>>>> or
>>>> the
>>>> method is the same as like 3D. thanks
>>>> 
>>>> Altaf Ur Rahman
>>>> PhD Research student
>>>> Department of Physics
>>>> University of Duisburg-Essen, Germany
>>>> 
>>>> 
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