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

• 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