[Pw_forum] Using mixture of pseudo potential

[Duy Le]

On Tue, May 31, 2011 at 2:24 PM, Vi Vo <vovi47 at yahoo.com> wrote:
> Hi Duy,
>
> Thanks.  I see it in the output, but I was not sure how the ecutrho is set
> for different PPs.   If only one ecutrho in set in one calculation, it is
> not a good idea to use a mixture of PPs, since then if ecutrho is set to be
> N*ecutwfc, the same value is used for NC PP.
>
I think it is not a good idea to have 2 or more ecutrho in a single
calculation because I don't know why we need to and how to implement
:-)
--------------------------------------------------
Duy Le
PhD Student
Department of Physics
University of Central Florida.

"Men don't need hand to do things"

> Vi
> ________________________________
> From: Duy Le <ttduyle at gmail.com>
> To: PWSCF Forum <pw_forum at pwscf.org>
> Sent: Tue, May 31, 2011 10:29:36 AM
> Subject: Re: [Pw_forum] Using mixture of pseudo potential
>
> On Tue, May 31, 2011 at 1:11 PM, Vi Vo <vovi47 at yahoo.com> wrote:
>> Hi Pine,
>>
>> Thank you.  Yes, I know that I have to do different tests for ecutrho and
>> ecutwfc, but my questions are different. I would like to know what is the
>> default setting for ecutrho the code would assume. I restate my question
>> as
>> follows:
>>
>> If I forgot to specify the ecutrho, what default value of  ecutrho would
>> the
>> code assume for US PP?  (I guess it still uses the default
>> ecutrho=4*ecutwfc).
>>
>> On the other hand, assuming I set the ecutrho=9*ecutwfc, does then the
>> same
>> value of ecutrho=8*ecutwfc also apply to NC PP, or does the value of
>> ecutrho=4*ecutwfc will be used for NC PP.
>
> If there is nothing changed, according to the QE manual, the default
> factor of 4 does not depend on the type of potential.
> Also, there is only one ecutrho in a single calculation, and it is
> written in the output (most of parameters can be found in the output).
>
>
>>
>> Thank you,
>>
> --------------------------------------------------
> Duy Le
> PhD Student
> Department of Physics
> University of Central Florida.
>
> "Men don't need hand to do things"
>
>> Vi
>>
>>
>> ________________________________
>> From: lucking-pine <songsong19840614 at gmail.com>
>> To: PWSCF Forum <pw_forum at pwscf.org>
>> Sent: Mon, May 30, 2011 9:35:59 PM
>> Subject: Re: [Pw_forum] Using mixture of pseudo potential
>>
>> Hi,
>> In my way,I usually test ecutrho = X*ecutwfc using scf or relax.I look the
>> result of total energy or enthalpy.
>> Such as:
>> 1.ecutwfc=47 ecutrho=400, total energy= -290.983
>> 2.ecutwfc=47 ecutrho=380, total energy= -290.993
>> So,I thought '2' is better than '1'.
>>
>> Bests,
>> Pine.
>> 2011/5/31 Vi Vo <vovi47 at yahoo.com>
>>>
>>> Dear All,
>>>
>>> In my calculation, I used a mixture of pseudo potentials, ie.
>>> norm-conserving pp (NC pp)  for one element and ultrasoft pp (US pp) for
>>> another.  If I don't specify ecutrho in the input, what will be the
>>> default
>>> value for ecutrho for the ultrasoft pp.  I know that for NC pp, ecutrho =
>>> 4*ecutwfc, but I do not know if the same value is used for US pp.  On the
>>> other hand, if I specify ecutrho = 8*ecutwfc, then does the same value
>>> apply
>>> to the NC pp.
>>>
>>> Thank you very much,
>>>
>>> Vi
>>> University of Houston
>>>
>>>
>>>
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>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
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>>
>>
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