[Pw_forum] (no subject)

[Paolo Giannozzi]

You can make a set of fixed-cell calculations. What you cannot do is a
variable-cell calculation. It is not just a problem of PP files: one
has to derive, or to find in the literature, the expression forstress
with meta-GGA, then to implement them in the code. It takes time and
effort.

PG

On Thu, Jun 29, 2017 at 4:38 AM, Hong Tang <tanghong992 at gmail.com> wrote:
> Dear Paolo:
>
> Thank you very much for helping. So there is no way I can do the lattice
> constance optimization right now with metaGGA functionals in QE, unless
> somebody can re-design the pp files. Is my understanding correct?
>
> Best regards,
>
> Hong Tang
>
>
>
> __________________________________________
>
> There isn't much to explain: nobody has ever written down and
> implemented  the formula for stress in the case of meta-GGA. In QE
> meta-GGA is implemented (sort of) only for norm-conserving
> pseudopotential, so there is no need (bot that I know) to store the
> kinetic energy density in the PP file
>
>
>
> Paolo
>
> On Wed, Jun 28, 2017 at 4:34 AM, Hong Tang <tanghong992 at gmail.com> wrote:
>> Dear Paolo:
>>
>>
>>
>> Thank you so much for helping.
>>
>> I tried grep -n “stress” Si.rx.out
>>
>> What I got is below:
>>
>> [hongtang at login4 results]$ grep -n "stress" Si.rx.out
>>
>> 1797:     entering subroutine stress ...
>>
>> 1799:     Message from routine stress:
>>
>> 1800:     Meta-GGA and stress not implemented
>>
>> 3128:     entering subroutine stress ...
>>
>> 3130:     Message from routine stress:
>>
>> 3131:     Meta-GGA and stress not implemented
>>
>> 4442:     entering subroutine stress ...
>>
>> 4444:     Message from routine stress:
>>
>> 4445:     Meta-GGA and stress not implemented
>>
>> 5764:     entering subroutine stress ...
>>
>> 5766:     Message from routine stress:
>>
>> 5767:     Meta-GGA and stress not implemented
>>
>> 7555:     entering subroutine stress ...
>>
>> 7557:     Message from routine stress:
>>
>> 7558:     Meta-GGA and stress not implemented
>>
>>
>>
>> It shows MetaGGA and stress not implemented.  Maybe this is the problem
>> there.
>>
>> I want to do structure optimization with metagga functional (TPSS here).
>> In
>> VASP, I know the pseudo potentials (pps) of the elements should have
>> “kinetic energy density”.  In quantum espresso, I don’t know what should
>> be
>> in the pps. The pps I chose for Si is for tpss, as you can see from the
>> input file.
>>
>>
>>
>> Please explain to me a bit more clear how to fix the problem. I appreciate
>> your helps very much.
>>
>>
>>
>> Hong Tang
>>
>> Temple University
>>
>> Philadelphia, PA 19122 US
>
>
> On Wed, Jun 28, 2017 at 10:37 PM, Hong Tang <tanghong992 at gmail.com> wrote:
>>
>> Dear Paolo:
>>
>> Thank you very much for helping. So there is no way I can do the lattice
>> constance optimization right now with metaGGA functionals in QE, unless
>> somebody can re-design the pp files. Is my understanding correct?
>>
>> Best regards,
>>
>> Hong Tang
>>
>>
>>
>> __________________________________________
>>
>> There isn't much to explain: nobody has ever written down and
>> implemented  the formula for stress in the case of meta-GGA. In QE
>> meta-GGA is implemented (sort of) only for norm-conserving
>> pseudopotential, so there is no need (bot that I know) to store the
>> kinetic energy density in the PP file
>>
>>
>>
>> Paolo
>>
>> On Wed, Jun 28, 2017 at 4:34 AM, Hong Tang <tanghong992 at gmail.com>
>> wrote:
>> > Dear Paolo:
>> >
>> >
>> >
>> > Thank you so much for helping.
>> >
>> > I tried grep -n “stress” Si.rx.out
>> >
>> > What I got is below:
>> >
>> > [hongtang at login4 results]$ grep -n "stress" Si.rx.out
>> >
>> > 1797:     entering subroutine stress ...
>> >
>> > 1799:     Message from routine stress:
>> >
>> > 1800:     Meta-GGA and stress not implemented
>> >
>> > 3128:     entering subroutine stress ...
>> >
>> > 3130:     Message from routine stress:
>> >
>> > 3131:     Meta-GGA and stress not implemented
>> >
>> > 4442:     entering subroutine stress ...
>> >
>> > 4444:     Message from routine stress:
>> >
>> > 4445:     Meta-GGA and stress not implemented
>> >
>> > 5764:     entering subroutine stress ...
>> >
>> > 5766:     Message from routine stress:
>> >
>> > 5767:     Meta-GGA and stress not implemented
>> >
>> > 7555:     entering subroutine stress ...
>> >
>> > 7557:     Message from routine stress:
>> >
>> > 7558:     Meta-GGA and stress not implemented
>> >
>> >
>> >
>> > It shows MetaGGA and stress not implemented.  Maybe this is the problem
>> > there.
>> >
>> > I want to do structure optimization with metagga functional (TPSS here).
>> > In
>> > VASP, I know the pseudo potentials (pps) of the elements should have
>> > “kinetic energy density”.  In quantum espresso, I don’t know what should
>> > be
>> > in the pps. The pps I chose for Si is for tpss, as you can see from the
>> > input file.
>> >
>> >
>> >
>> > Please explain to me a bit more clear how to fix the problem. I
>> > appreciate
>> > your helps very much.
>> >
>> >
>> >
>> > Hong Tang
>> >
>> > Temple University
>> >
>> > Philadelphia, PA 19122 US
>
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum



-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222