Optics at the independent particle level: Difference between revisions

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In this tutorial you will learn how to calculate optical spectra at the RPA or independent particle level for bulk hBN.
In this tutorial you will learn how to calculate optical spectra at the RPA or independent particle level for bulk hBN.


[[File:CH1.png|200px|Yambo tutorial image]]
[[File:CH1.png|x50px|Yambo tutorial image]]


[[File:Ehf.png|200px|caption]] 
== Prerequisites ==


== Prerequisites ==
* You must first complete the "How to use Yambo" tutorial
'''Previous modules'''
* You must have completed all "How to use Yambo" modules


'''You will need''':
'''You will need''':
* The <code>SAVE</code> databases for bulk hBN ('''Download here''')
* The <code>SAVE</code> databases for bulk hBN  
* The <code>yambo</code> executable
* The <code>yambo</code> executable
* <code>gnuplot</code>, for plotting spectra
* <code>gnuplot</code>, for plotting spectra


== Choosing input parameters ==
== Choosing input parameters ==
Enter the folder for bulk hBN that contains the SAVE directory. If you have already worked in this folder, you might like to clean up any old files, and run the initialization again:
Enter the folder for bulk hBN that contains the SAVE directory, and generate the input file. From <code>yambo -H</code> you should understand that the correct option is <code>yambo -o c</code>. Let's add some command line options:
<!--If you have already worked in this folder, you might like to clean up any old files, and run the initialization again:
  cd YAMBO_TUTORIALS/hBN/YAMBO
  cd YAMBO_TUTORIALS/hBN/YAMBO
  rm yambo.in SAVE/ndb.*  
  rm yambo.in SAVE/ndb.*  
  yambo  
  yambo  
Take care to '''not''' delete the <code>ns.*</code> files.
Take care to '''not''' delete the <code>ns.*</code> files. -->
 
$ cd YAMBO_TUTORIALS/hBN/YAMBO
Now let's generate the input file. From <code>yambo -H</code> you should understand that the correct option is <code>yambo -o c</code>. Let's add some command line options:
  $ yambo -o c -F yambo.in_IP -J Full
  yambo -o c -F yambo.in_IP -J Full
This corresponds to optical properties in G-space at the independent particle level (<code>Chimod= "IP"</code>).
This corresponds to optical properties in G-space at the independent particle level (<code>Chimod= "IP"</code>).
Let's calculate just for ''q''->0, which is always the first q-point, by changing the appropriate flag in the input file:
Let's calculate just for ''q''->0, which is always the first q-point, by changing the appropriate flag in the input file:

Revision as of 17:11, 24 March 2017

In this tutorial you will learn how to calculate optical spectra at the RPA or independent particle level for bulk hBN.

Yambo tutorial image

Prerequisites

  • You must first complete the "How to use Yambo" tutorial

You will need:

  • The SAVE databases for bulk hBN
  • The yambo executable
  • gnuplot, for plotting spectra

Choosing input parameters

Enter the folder for bulk hBN that contains the SAVE directory, and generate the input file. From yambo -H you should understand that the correct option is yambo -o c. Let's add some command line options:

$ cd YAMBO_TUTORIALS/hBN/YAMBO
$ yambo -o c -F yambo.in_IP -J Full

This corresponds to optical properties in G-space at the independent particle level (Chimod= "IP"). Let's calculate just for q->0, which is always the first q-point, by changing the appropriate flag in the input file:

% QpntsRXd
 1 |  1 |                   # [Xd] Transferred momenta
%

Save the input file and launch the code, keeping the command line options as before (i.e., just remove the lower case options):

$ yambo -F yambo.in_IP -J Full
...
 <---> [05] Optics
<---> [LA] SERIAL linear algebra
<---> [DIP] Checking dipoles header
<---> [x,Vnl] computed using 4 projectors
<---> [M  0.017 Gb] Alloc WF ( 0.016)
<---> [WF] Performing Wave-Functions I/O from ./SAVE
<01s> Dipoles: P and iR (T): |########################################| [100%] 01s(E) 01s(X)
<01s> [M  0.001 Gb] Free WF ( 0.016)
<01s> [DIP] Writing dipoles header
<01s> [X-CG] R(p) Tot o/o(of R)  :   5501   52992     100
<01s> Xo@q[1] |########################################| [100%] --(E) --(X)
<01s> [06] Game Over & Game summary