Page **1** of **1**

### How to plot exciton wave function in reciprocal space?

Posted: **Fri Nov 08, 2019 6:26 am**

by **Dean**

Dear all,

I want to plot exciton wave function in reciprocal space, how to do that?

Thanks in advance.

### Re: How to plot exciton wave function in reciprocal space?

Posted: **Fri Nov 08, 2019 10:38 am**

by **Daniele Varsano**

Deaer Yimin,

By using ypp, (ypp -a) you can analyze the weight of an exciton.

In the output file o.exc_weights_at* you have the transitions participating in the excitation. The files contain the transitions indicating valence and conduction bands at each k points with its weight, but also (commented) the values for each k point integrated on bands. From there you can plot the exc-wf in reciprocal space.

Some tips:

1) In order to have the transition, the flag WRbsWF should be activated when diagonalizing the BSE

2) weights of the excitonic wavefunction are plots if they are above a threshold. By default, it is 5% of the max weight, but you can change from input by changing MinWeight variable to zero (ypp -a -V all)

3) Exciton closed in energy (degenerates, or nearly degenerate) are grouped, in case you have excitations close in energy if you want to analyze just one exciton set Degen_Step=0.

Best,

Daniele

### Re: How to plot exciton wave function in reciprocal space?

Posted: **Wed May 06, 2020 1:29 pm**

by **claudio**

Dr. Yimin Ding

there a tutorial on how to plot excitons in reciprocal space using yambopy,

have a look here:

http://www.yambo-code.org/wiki/index.ph ... ocal_space
best

Claudio