Is it equivalent to the regular adopted Ewald summation method in mathematics?
I think you forgot to attach the paper in question...
That said, if there is not lo-to splitting, there are no effectiv
charges and no long-range interaction. Than there is no problem doing
Fourier interpolation.
2D is a bit special, but the QE code has special techniques to deal with
2D phonon interpolation, I think it is explained in Phys. Rev. B 94, 085415
cheers
With thanks and best regards !
Happy New Year !
--
Jian-qi Huang
Magnetism and Magnetic Materials Division
Institute of Metal Research
Chinese Academy of Sciences
72 Wenhua Road, Shenyang 110016, China
email:[email protected]
-----原始邮件-----
发件人: "Lorenzo Paulatto" <[email protected]>
发送时间: 2020-01-09 03:56:21 (星期四)
收件人: [email protected]
抄送:
主题: Re: [QE-users] phonon dispersion relation from the full IFCs
Thank you for reply, professor. I understand the regular routine
implemented in QE where the long-range contribution is added in
reciprocal space. My point is can I get the correct dynamical matrix
just by making inverse Fourier transformation of the full(short+long)
IFCs in a large real space?
The dynamical matrix at Gamma is discontinuity with respect to the
points nearby, which would make any Fourier transform impossible to
converge.
I think you should explain WHY you want to do this, and you may get some
better answer.
In practice, if I was obliged at gunpoint, I would replace the dynamical
matrix file at Gamma (typically dyn1) with one computed very close to
Gamma, let's say q=0.001,0,0. Edit the file to trick q2r into thinking
that it was done at exactly Gamma, and see was comes out.
If the material has a non-analytic term (i.e. the long range term
depends on the direction), this will definitely not work. Otherwise, you
may get something decent.
cheers
--
Lorenzo Paulatto - Paris
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_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
--
Lorenzo Paulatto - Paris
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
users mailing list [email protected]
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