[QE-users] Doubt about Hands-on QE summer school TD-DFT exercise (day 3)

[Iurii TIMROV]

Dear Xavier,


> Can I use the values obtained with Turbo_Lanczos to plot the other optical properties (refractive index, extinction coefficient, absorption, loss function, reflectivity, and conductivity) by applying the equations in M Jubair et al 2019 J. Phys. Commun. 3 055017 or should I use different methods?


Yes, you can do that. But I recommend you to check carefully other literature for various levels of theory/approximations for computing the optical properties of molecules and solids. One good reference is https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.74.601


BTW, there is the turboEELS code in the TDDFPT package to compute the loss function.


HTH


Iurii


--
Dr. Iurii TIMROV
Senior Research Scientist
Theory and Simulation of Materials (THEOS)
Swiss Federal Institute of Technology Lausanne (EPFL)
CH-1015 Lausanne, Switzerland
+41 21 69 34 881
http://people.epfl.ch/265334
________________________________
From: José Xavier <jxln_karate at yahoo.com.br>
Sent: Saturday, May 27, 2023 1:56:49 AM
To: Quantum ESPRESSO Users Forum; Iurii TIMROV
Subject: Re: Doubt about Hands-on QE summer school TD-DFT exercise (day 3)

Dear Dr. Timrov,

Thank you again for your help.
So, since the aim was to compare the absorption curve obtained with epsilon.x, turbo_Lanczos, and turbo_Davidson, the value was relevant. Ok.

One last question.
Can I use the values obtained with Turbo_Lanczos to plot the other optical properties (refractive index, extinction coefficient, absorption, loss function, reflectivity, and conductivity) by applying the equations in M Jubair et al 2019 J. Phys. Commun. 3 055017 or should I use different methods?

For example, the refractive index is obtained by:

n(ω) = 1/(2)**1/2 [(ε1(ω)**2 - ε2(ω)**2)**1/2 - ε1(ω)]**1/2


Thanks for your help

Xavier
Universidade Federal do Rio Grande do Norte
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20230527/dbd3a0b3/attachment.html>