Computation of crystal elastic constants using effective pair and three body potentials. Pair and three body potentials can be represented as explicit or implicit functions. In the latter case potential energy is calculated using FEM simulation.
The main module is elastic_const.elastic_const_computation. It offers
two functions to compute elastic constants compute_constants_xy_method
and compute_constants_r_method. They differ by how the consider
potential functions. In the compute_constants_xy_method potential
function is represented as a function which accepts x and y coordinates
of the particles. And compute_constants_r_method considers potentials
as functions which accept distances between particles. Actual
implementations of these methods are in the modules
elastic_const.xy_method and elastic_const.r_method.
Module elastic_const.xy_method is designed to work with classes
PairFemSimulation, TripletFemSimulation,
PairForceDerivativeComputation, TripletForceDerivativeComputation,
which are wrappers for external FEM simulation program. Module
r_method is designed to work with generic two and three body
potentials.