[Pw_forum] question on the lplot_drho variable of turbo_davidson

[xiaochuan Ge]

​Dear Giuseppe,

Sorry for the delay. That might be some bugs in the plot_drho calculation,
but I do not have your input file for the ground state calculation, so I
cannot reproduce your error. I tried to do this calculation with another
system, everything works fine. Can you follow the example and double check
your input? If it still doesn't work please send me all your input files.

Regarding the response density, I am afraid you do have a misunderstanding.
Since we are using the linear response approach, the response density is
|H+L|^2 -|H|^2 ~= 2H*L
which means you should take the product of Homo and Lumo. If you plot both
the Homo and Lumo, what you should expect for the response density if a
product of these two orbitals, instead of charge depletion and charge
accumulation. If you would like to know details of how the response density
is defined in TDDFT at QE, I suggest you to read this paper:
J. Chem. Phys. 128, 154105 (2008)

I wish my answer helps, please do not hesitate to let me know if you want
to discuss more.

Best,

On 29 January 2016 at 10:52, Giuseppe Mattioli <giuseppe.mattioli at ism.cnr.it
> wrote:

> Neither I in the case of a symmetric water molecule. I was only trying to
> say that the plotted quantity could not be the total density of the S1*
> state because it contains a negative and a positive part. In a "naif" view
> I would say that if a given electronic transition is almost totally
> projected on the HOMO-->LUMO vector, then the lplot_drho plot should show
> charge depletion on the HOMO and charge accumulation on the LUMO
>



===================
Dr. Xiaochuan Ge (Giovanni)
Center for Functional Nanomaterials
Brookhaven national laboratory
===================
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20160204/ed537548/attachment.html>