<filename>Asap-3.8.4/Test/LJ_Stress.py
from numpy import *
from asap3 import *
from ase.lattice.compounds import B2
from asap3.testtools import ReportTest

atoms = B2(size=(332,166,5), symbol=('Cu', 'Zr'), latticeconstant=2.7)
lj = LennardJones((29,40), 0.2*array([0.5, 1.0, 1.0, 0.5]),
                  array([1.236, 2.0, 2.0, 2.352]),
                  rCut=2.0*2.352)
atoms.set_calculator(lj)

# If the following line is included, the bug is not seen.
#atoms.get_potential_energy()
stress = atoms.get_stress()
exp_tr = 9.30356046e-02
for i in range(3):
    ReportTest("Diagonal elements of stress tensor", stress[i], exp_tr, 1e-6)
for i in range(3,6):
    ReportTest("Off-diagonal elements of stress tensor", stress[i], 0.0, 1e-8)
    
ReportTest.Summary()
