Angular dependence of non-linear response

In this tutorial we show how to calculate angular dependence of non-linear response using Yambo. (This tutorial requires Yambo > 5.3)
We consider as example a monolayer hBN, DFT input files can be downloaded here: hBN-2D-RT.tar.gz
In this tutorial we suppose you already know how to calculate non-linear reponse with Yambo,
if this is not the case please have a look to the tutorials: Non linear response

Run DFT calculation, import the wave-function and run the setup. Then

Remove symmetries

We remove symmetries in all the plane where we want to study the angular dependence Using the command ypp_nl -y

fixsyms                          
# [R] Remove symmetries not consistent with an external perturbation
% Efield1
  0.000000 | 1.000000 | 0.000000 |        # First external Electric Field
%
% Efield2
   1.000000 | 0.000000 | 0.000000 |        # Additional external Electric Field
%
BField= 0.000000           T     # [MAG] Magnetic field modulus
Bpsi= 0.000000             deg   # [MAG] Magnetic field psi angle [degree]
Btheta= 0.000000           deg   # [MAG] Magnetic field theta angle [degree]
RmTimeRev                     # Remove Time Reversal

then go in the FixSymm folder and run the setup again