[Pw_forum] RRKJ pseudopotentials and raman calculations

[Merlin Meheut]

Paolo Giannozzi a écrit :
> Merlin Meheut wrote:
>
>   
>> I would like to know if there is a fundamental difference between 
>> rrkj pseudopotentials generated with the opium software and rrkj"us" 
>> pseudopotentials, such as the carbon pseudopotential C.pbe-rrkjus.UPF 
>> present on your website. Apparently, the former work for Raman 
>> calculations, on the same level as trouillier-martins, whereas the 
>> latter is considered as "ultrasoft" and therefore the calculation crashes
>>     
>
> the calculation doesn't "crash", it stops with an error message.
> C.pbe-rrkjus.UPF is not "considered" ultrasoft: it "is" ultrasoft,
> obtained by ultrasoft pseudization of a hard norm-conserving
> pseudopotential. The latter is (usually but not necessarily)
> generated using the RRKJ (Rabe-Rappe-Kaxiras-Joanoupoulos)
> algorithm. This is why they are called "rrkjus". Norm conserving
> PP generated by ld1.x using the RRKJ pseudization should be more
> or less the same as those generated by OPIUM (just a guess, I never
> tried to compare them)
>
>   
>> For my use, these rrkj pseudopotentials are perfect
>>     
>
> No problem, use them
>
> P.
>   

Dear Paolo,

If I have well understood what you said, rrkj ("optimized") 
pseudopotentials generated with opium are also ultrasoft.
In this case, I would like to understand why pwscf does not stop with an 
error message when doing raman calculations
with these pseudopotentials.

Sincerely,

Merlin



-- 
Merlin Méheut
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LMTG- Université Paul Sabatier Toulouse 3
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