[Q-e-developers] [Pw_forum] a question about BORN Effective charges

[Paolo Giannozzi]

Update: the two ways to compute effective charges, dF/dE and dP/du,
differ in the presence of nonlinear core corrections AND gradient
corrections; with NLCC and LDA they are the same. Any idea?

Paolo

On Wed, Apr 26, 2017 at 6:42 PM, Paolo Giannozzi <p.giannozzi at gmail.com> wrote:
> ... and this since at least v.4.3.2! See attached example
>
> Paolo
>
> On Wed, Apr 26, 2017 at 10:08 AM, Paolo Giannozzi <p.giannozzi at gmail.com> wrote:
>> There is a bug, likely in the dF/dE calculation, when pseudopotentials
>> have nonlinear core corrections
>>
>> Paolo
>>
>> On Sat, Apr 22, 2017 at 7:33 PM, VineetKumar Pandey
>> <vineetkumar.pandey at students.iiserpune.ac.in> wrote:
>>> sir I performed phonon calculation for monolayer PbI2 . but I am getting
>>> born effective charges calculated by two ways (one is dF/dE and other is
>>> dPdu) , are quite different . i am sending you my input files .
>>>
>>>
>>>
>>>  Effective charges (d Force / dE) in cartesian axis
>>>
>>>            atom      1   I
>>>       Ex  (       -2.21984        0.00000        0.00000 )
>>>       Ey  (        0.00000       -2.21984        0.00000 )
>>>       Ez  (        0.00000        0.00000       -0.36016 )
>>>            atom      2   Pb
>>>       Ex  (        3.72748        0.00000        0.00000 )
>>>       Ey  (        0.00000        3.72748        0.00000 )
>>>       Ez  (        0.00000        0.00000        0.57697 )
>>>            atom      3   I
>>>       Ex  (       -1.93678        0.00000        0.00000 )
>>>       Ey  (        0.00000       -1.93678        0.00000 )
>>>       Ez  (        0.00000        0.00000       -0.36018 )
>>>
>>>           Effective charges (d P / du) in cartesian axis
>>>
>>>            atom      1   I
>>>       Px  (       -1.99748        0.00000        0.00000 )
>>>       Py  (        0.00000       -1.99748        0.00000 )
>>>       Pz  (        0.00000        0.00000       -0.30196 )
>>>            atom      2   Pb
>>>       Px  (        3.99223        0.00000        0.00000 )
>>>       Py  (        0.00000        3.99223        0.00000 )
>>>       Pz  (        0.00000        0.00000        0.60413 )
>>>            atom      3   I
>>>       Px  (       -1.99741        0.00000        0.00000 )
>>>       Py  (        0.00000       -1.99741        0.00000 )
>>>       Pz  (        0.00000        0.00000       -0.30197 )
>>>
>>>
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>>
>>
>>
>> --
>> 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
>
>
>
> --
> 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



-- 
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