TUTORIAL ON LINEAR AND NON-LINEAR RESPONSES TO ELECTRIC FIELDS

Summary_NLO.txt
summary of the results obtained for various properties using either
response function or finite difference techniques.

PART0-STRUCT
structural optimization of AlAs to be used all along the tutorial
(i.e. recomputed with the convergence parameters of the tutorial)

PART1-DFPT
Linear and non-linear responses of AlAs to electric field and
atomic displacements using DFPT.

PART2-BERRY
Berry phase calculation under zero field to get different linear
and non-linear responses from finite differences

PART3-EFIELD
Finite electric field calculation using the method of Souza and
Vanderbilt, to get different linear and non-linear responses
from finite differences.
