def spin_system_from_p_state(p_state, idx_image=-1, copy=False):
from spirit import geometry, system
spin_system = Spin_System()
spin_system.positions = geometry.get_positions(p_state, idx_image = idx_image)
spin_system.spins = system.get_spin_directions(p_state, idx_image = idx_image)
spin_system.n_cell_atoms = geometry.get_n_cell_atoms(p_state)
spin_system.n_cells = geometry.get_n_cells(p_state)
if copy:
spin_system.positions = np.array(spin_system.positions )
spin_system.spins = np.array(spin_system.spins )
spin_system.n_cell_atoms = np.array(spin_system.n_cell_atoms)
spin_system.n_cells = np.array(spin_system.n_cells )
return spin_system
def test_energy(self, p_state, mu=None):
nos = system.get_nos(p_state)
pos = np.array(geometry.get_positions(p_state)).reshape(nos, 3)
spins = np.array(system.get_spin_directions(p_state)).reshape(nos, 3)
if type(mu) == type(None):
mu_s = np.ones(len(pos))
else:
mu_s = mu
E_BF = self.E_DDI_BF(pos, spins, mu_s)
E_Spirit = system.get_energy(p_state)
return E_BF, E_Spirit
def run(self):
passed = True
l_cube = 100
radius = l_cube / 4
with state.State(self.inputfile, quiet=True) as p_state:
configuration.plus_z(p_state)
simulation.start(p_state,
simulation.METHOD_LLG,
simulation.SOLVER_SIB,
n_iterations=1)
system.update_data(p_state)
#query some quantities
nos = system.get_nos(p_state)
field = np.array(system.get_effective_field(p_state)).reshape(
nos, 3)
pos = np.array(geometry.get_positions(p_state)).reshape(nos, 3)
spins = np.array(system.get_spin_directions(p_state)).reshape(
nos, 3)
#get quantitities in sphere
center = np.array([l_cube / 2, l_cube / 2, l_cube / 2], dtype=int)
idx_in_sphere = np.linalg.norm(pos - center, axis=1) <= radius
mu_s = np.array([1 if idx_in_sphere[i] else 0 for i in range(nos)])
# field_bf = self.Gradient_DDI_BF(pos, spins, mu_s)
# field_bf_in_sphere = field_bf[idx_in_sphere]
field_in_sphere = field[idx_in_sphere]
# deviation_sphere = np.std(field_in_sphere - mean_grad_sphere, axis=0)
theory = np.array(
[0, 0, 1]) * 2 / 3 * self.mu_0 * self.mu_B * self.mu_B * 1e30
print("Mean field = ",
np.mean(field / self.mu_B, axis=0))
# print("Mean field (BF) = ", np.mean(field_bf/self.mu_B, axis=0))
print("Mean field in sphere = ",
np.mean(field_in_sphere / self.mu_B, axis=0))
# print("Mean field in sphere (BF) = ", np.mean(field_bf_in_sphere/self.mu_B, axis=0))
print("Theory = ", theory)
return passed
def test_positions(self):
positions = geometry.get_positions(self.p_state)
# spin at (0,0,0)
self.assertAlmostEqual(positions[0][0], 0)
self.assertAlmostEqual(positions[0][1], 0)
self.assertAlmostEqual(positions[0][2], 0)
# spin at (1,0,0)
self.assertAlmostEqual(positions[1][0], 1)
self.assertAlmostEqual(positions[1][1], 0)
self.assertAlmostEqual(positions[1][2], 0)
# spin at (0,1,0)
self.assertAlmostEqual(positions[2][0], 0)
self.assertAlmostEqual(positions[2][1], 1)
self.assertAlmostEqual(positions[2][2], 0)
# spin at (1,1,0)
self.assertAlmostEqual(positions[3][0], 1)
self.assertAlmostEqual(positions[3][1], 1)
self.assertAlmostEqual(positions[3][2], 0)
def test_gradient(p_state, mu = None):
nos = system.get_nos(p_state)
pos = np.array(geometry.get_positions(p_state)).reshape(nos, 3)
spins = np.array(system.get_spin_directions(p_state)).reshape(nos, 3)
simulation.start(p_state, simulation.METHOD_LLG, simulation.SOLVER_SIB, n_iterations=1)
system.update_data(p_state)
if type(mu) == type(None):
mu_s = np.ones(len(pos))
else:
mu_s = mu
Gradient_BF = Gradient_DDI_BF(pos, spins, mu_s)
Gradient_Spirit = np.array(system.get_effective_field(p_state)).reshape(nos, 3)
return Gradient_BF, Gradient_Spirit
def plot_basis_cell(p_state, ax=None):
from spirit import geometry, system
# Read out the information we need
n_cell_atoms = geometry.get_n_cell_atoms(p_state)
n_cells = geometry.get_n_cells(p_state)
positions = geometry.get_positions(p_state)
def idx(i,a,b,c):
return i + n_cell_atoms * (a + n_cells[0] * (b + n_cells[1] * c))
# Draw the outlines of the basis cell
lattice_points = np.array([ positions[idx(0,0,0,0)], positions[idx(0,1,0,0)], positions[idx(0,1,1,0)], positions[idx(0,0,1,0)] ])
patch=[Polygon(lattice_points[:,:2])]
pc = PatchCollection(patch, linestyle="--", facecolor = [0,0,0,0], edgecolor = [0,0,0,1])
ax.add_collection(pc)
ax.scatter(positions[:n_cell_atoms,0], positions[:n_cell_atoms,1], color="red", s=100)
ax.set_xlabel(r"$x\;\;[\AA]$")
ax.set_ylabel(r"$y\;\;[\AA]$")