center_of_charge = (a / 2, a / 2, 3 * a / 4) # off center charge
Nc = (N, N, N) # Number of grid points along each axis
gd = GridDescriptor(Nc, (a, a, a), 0) # Grid-descriptor object
solver = PoissonSolver(nn=3, use_charge_center=True)
solver.set_grid_descriptor(gd)
solver.initialize()
gauss = Gaussian(gd, a=inv_width, center=center_of_charge)
test_poisson = Gaussian(gd, a=inv_width, center=center_of_charge)
# /-------------------------------------------------\
# | Check if Gaussian potentials are made correctly |
# \-------------------------------------------------/
# Array for storing the potential
pot = gd.zeros(dtype=float, global_array=False)
solver.load_gauss()
vg = test_poisson.get_gauss_pot(0)
# Get analytic functions
ng = gauss.get_gauss(0)
# vg = solver.phi_gauss
# Solve potential numerically
niter = solver.solve(pot, ng, charge=1.0, zero_initial_phi=False)
# Determine residual
# residual = norm(pot - vg)
residual = gd.integrate((pot - vg)**2)**0.5
print('residual %s' % (
residual))
assert residual < 1e-5 # Better than 5.x
# mpirun -np 2 python gauss_func.py --gpaw-parallel --gpaw-debug
