[Pw_forum] wave function cutoff range for pseudopotentials

B S Bhushan ecebhushan at gmail.com
Thu Aug 24 15:43:26 CEST 2017


Thank you Dr. Tan.

On Thu, Aug 24, 2017 at 5:36 PM, Tan Hengxin <tanhx90 at gmail.com> wrote:

> Dear Bhushan,
>
> The best cutoff energy should be the well tested one, which satisfies your
> requests. Generally, I would use the largest cutoff energy for the
> wavefunction in the pseudopotential files as the start point.
>
> I don't think there is a very clear boundary line between uspp and ncpp,
> and, the energy range of ncpp can also be very large. Generally, ncpp would
> be more expensive than uspp.
> What kind of pseudopotential you use should depend on your request again.
> Nobody requires that you must us this or that kind of pseudopotential. The
> one that gives the real physics is the best one.
>
> Best,
> Tan
> THU
>
> On Thu, Aug 24, 2017 at 7:33 PM, B S Bhushan <ecebhushan at gmail.com> wrote:
>
>> Dear Experts,
>>
>> I'm new to Quantum Espresso. As a starter, I have got few questions while
>> performing simulations.
>>
>> (1) In what range the wavefunction cutoff range for Ultrasoft,
>> normconserving and PAW pseudopotentials lies?
>> I read on google that, for ultrasoft pseudopotentials the wavefunction
>> cutoff ranges from 20-50 Ry, while for norm-conserving pseudopotentials it
>> is from 60-100 Ry. Is it correct ?. or the norm-conserving pseudopotentials
>> can also have range starting from 20-100 Ry ?.
>>
>> (2) I am simulating defects in graphene. Which pseudopotential should I
>> prefer for graphene, Ultrasoft or Norm-conserving or PAW ?
>>
>>
>> I am really thankful for your valuable time and knowledge.
>>
>> Thank you.
>>
>>
>> Sincerely,
>> B. S. Bhushan,
>> CNT Laboratory,
>> ABV - Indian Institute of Information Technology and Management,
>> Gwalior, India.
>>
>>
>> _______________________________________________
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
>
> --
>
> Tan Hengxin
> Department of physics, THU.
> Beijing 100084, China
> Office: B403,New Science Building
> E-mail:t <E-mail%3Athx13 at mails.tsinghua.edu.cn>anhx90 at gmail.com
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170824/f9f49942/attachment.html>


More information about the users mailing list