[Pw_forum] Interpolation method used in getting projector in k-space

[Ryky Nelson]

Hello Paolo,

thank you for the information!

Ryky Nelson
Institut für Anorganische Chemie
RWTH Aachen University

On Fri, Jun 17, 2016 at 5:20 PM, Paolo Giannozzi <p.giannozzi at gmail.com>
wrote:

> The Fourier-Bessel transformation was tested once upon a time, but it
> had a funny behavior sometimes and it was finally abandoned; the
> Fourier transforms of the radial parts are done in a rather dumb way,
> by computing the integrals \beta_l(q_i) = \int 4\pi r^2 \beta(r)
> j_l(q_ir) dr  on a uniform grid of q_i, interpolating them (optionally
> with splines, with a simple interpolation formula otherwise) for the
> required q=|k+G|
>
> Paolo
>
> On Fri, Jun 17, 2016 at 1:49 PM, Ryky Nelson <nelson.ryky at gmail.com>
> wrote:
> > Hello Paolo,
> >
> > I just want to know what kind of algorithm (method) used to
> > 3D-Fourier-transform and interpolate the projectors (beta functions).
> Does
> > it use the Fourier-Bessel transformation and Spline interpolation,
> > respectively? And thank you for the information of the subroutines.
> >
> > Ryky Nelson
> > Institut für Anorganische Chemie
> > RWTH Aachen University
> >
> > On Fri, Jun 17, 2016 at 12:20 PM, Paolo Giannozzi <p.giannozzi at gmail.com
> >
> > wrote:
> >>
> >> I am not sure I understand your questions. Projectors, aka "beta
> >> functions", are computed in reciprocal space (variable "vkb") by
> >> routine "init_us_2", using interpolation from a table computed by
> >> routine "init_us_1"
> >>
> >> Paolo
> >>
> >> On Thu, Jun 16, 2016 at 2:33 PM, Ryky Nelson <nelson.ryky at gmail.com>
> >> wrote:
> >> > Hello QE users and developers,
> >> >
> >> > in the PAW scheme, there's a step to calculate wave-function
> characters
> >> > at a
> >> > given k-point, i.e. <p_tilde (k) | psi_tilde(k)>. However, projectors
> >> > (p_tilde) are given in real-space in UPF files whereas the smooth
> >> > wave-functions are expanded in G(reciprocal)-space. Could someone tell
> >> > me
> >> > how and in what subroutine(s) this wave-function character is
> calculated
> >> > in
> >> > Espresso? Also, is there any interpolation method used in this
> >> > calculation?
> >> >
> >> > Thank you!
> >> >
> >> > Ryky Nelson
> >> > Institut für Anorganische Chemie
> >> > RWTH Aachen University
> >> >
> >> > _______________________________________________
> >> > 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
> >>
> >> _______________________________________________
> >> Pw_forum mailing list
> >> Pw_forum at pwscf.org
> >> http://pwscf.org/mailman/listinfo/pw_forum
> >
> >
> >
> > _______________________________________________
> > 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
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20160618/0d8d0b46/attachment.html>