Optics at the independent particle level

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

Prerequisites

Previous modules

• You must have completed all "How to use Yambo" modules

You will need:

• The SAVE databases for bulk hBN (Download here)
• The yambo executable
• gnuplot, for plotting spectra

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:

cd YAMBO_TUTORIALS/hBN/YAMBO
rm yambo.in SAVE/ndb.* 
yambo 

Take care to not delete the ns.* files.

Now let's 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:

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