Thank you Giuseppe for your answer.
Best,
Pascal
Le 29 juil. 2015 à 23:26, Giuseppe Mattioli a
écrit :
>
> Dear Pascal
> If I remember well, you can obtain the cell dipole trajectory by
> adding assume_isolated='mp' to your cp.x molecular dynamics input of a
> system contained in a cubic
Dear Yin,
You already got great suggestions. I would like to add one more option to
calculate IR from ab initio MD. You could do scf calculation on each
configuration obtained via MD to calculate Maximally Localized Wannier
Functions (MLWF). From MLWF you could calculate the dipole moment of th
Dear Pascal
If I remember well, you can obtain the cell dipole trajectory by
adding assume_isolated='mp' to your cp.x molecular dynamics input of a
system contained in a cubic cell (mp is defined for cubic cells only).
But the system should be really "isolated" (e.g., a molecule with its
c
Thank you Paolo and Nicola for your answer.
Best
Pascal
Le 29 juil. 2015 à 18:16, Paolo Giannozzi a écrit :
> From the FFTs of the atomic velocity autocorrelation function you can extract
> phonon frequencies, but you do not get "true" spectra
>
> Paolo
>
> On Wed, Jul 29, 2015 at 6:08 PM, P
>From the FFTs of the atomic velocity autocorrelation function you can
extract phonon frequencies, but you do not get "true" spectra
Paolo
On Wed, Jul 29, 2015 at 6:08 PM, Pascal Boulet
wrote:
> Hello,
>
> Isn’t it possible to get IR spectra from the FFTs of the atomic velocity
> autocorrelatio
On 29/07/2015 18:08, Pascal Boulet wrote:
> Hello,
>
> Isn’t it possible to get IR spectra from the FFTs of the atomic velocity
> autocorrelation function?
>
> Pascal
>
Hi Pascal,
that would give you the vibrational density of states - to get an IR
spectrum you need to understand how the system
Hello,
Isn’t it possible to get IR spectra from the FFTs of the atomic velocity
autocorrelation function?
Pascal
Le 29 juil. 2015 à 17:58, Nicola Marzari a écrit :
>
> Dear Yin,
>
>
> you need to calculate at every time step the total dipole in the unit
> cell, and then do the fourier tran
Dear Yin,
you need to calculate at every time step the total dipole in the unit
cell, and then do the fourier transform of the autocorrelation - see e.g.
here: http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.81.1235 or many
other papers published on the topic.
Note that if you do Car-Parrin
Dear Quantum Espresso developers,
I want to obtain IR spectra of crystals at room temperature. Considering the
temperature effect, I decided to use CPMD. I wonder whether it is possible to
get IR spectra from CPMD trajectory in Quantum Espresso?
What's more, can I involve vdw-correction in CPM
