[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.
> 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.
>> B. S. Bhushan,
>> CNT Laboratory,
>> ABV - Indian Institute of Information Technology and Management,
>> Gwalior, India.
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
> 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
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