def test_pbs_fail(self, setup):
with pytest.raises(ValueError):
BandStructure(setup.s1, [[0] * 3, [.5] * 3, [.25] * 3], 1)
with pytest.raises(ValueError):
BandStructure(setup.s1, [[0] * 3, [.5] * 3, [.25] * 3],
[1, 1, 1, 1])
with pytest.raises(ValueError):
BandStructure(setup.s1, [[0] * 3, [.5] * 3, [.25] * 3], [1, 1, 1])
def test_bs_insert_jump_fail(self):
g = geom.graphene()
nk = 10
bs = BandStructure(g,
[[0] * 3, [0.5, 0, 0], None, [0] * 3, [0., 0.5, 0]],
nk, ['A', 'B', 'C', 'D'])
d = np.empty([nk + 1])
with pytest.raises(ValueError):
bs.insert_jump(d)
def test_eig3(self, setup):
setup.HS.construct([(0.1, 1.5), ((1., 1.), (0.1, 0.1))])
BS = BandStructure(setup.HS, [[0, 0, 0], [0.5, 0.5, 0]], 10)
eigs = BS.asarray().eigh()
assert len(BS) == eigs.shape[0]
assert len(setup.HS) == eigs.shape[1]
eig2 = np.array([eig for eig in BS.asyield().eigh()])
assert np.allclose(eigs, eig2)
setup.HS.empty()
def test_berry_phase_loop(self, setup):
g = setup.g.tile(2, 0).tile(2, 1).tile(2, 2)
H = Hamiltonian(g)
bz1 = BandStructure.param_circle(H, 20, 0.01, [0, 0, 1], [1 / 3] * 3)
bz2 = BandStructure.param_circle(H,
20,
0.01, [0, 0, 1], [1 / 3] * 3,
loop=True)
assert np.allclose(berry_phase(bz1), berry_phase(bz2))
def test_bs_jump_skipping_none(self):
g = geom.graphene()
bs1 = BandStructure(
g, [[0] * 3, [0.5, 0, 0], None, [0] * 3, [0., 0.5, 0]], 30,
['A', 'B', 'C', 'D'])
bs2 = BandStructure(
g, [[0] * 3, [0.5, 0, 0], None, [0] * 3, [0., 0.5, 0], None], 30,
['A', 'B', 'C', 'D'])
assert np.allclose(bs1.k, bs2.k)
def test_pbz1(self, setup):
bz = BandStructure(setup.s1, [[0] * 3, [.5] * 3], 300)
assert len(bz) == 300
bz2 = BandStructure(setup.s1, [[0] * 2, [.5] * 2], 300, ['A', 'C'])
assert len(bz) == 300
bz3 = BandStructure(setup.s1, [[0] * 2, [.5] * 2], [150] * 2)
assert len(bz) == 300
bz.lineartick()
bz.lineark()
bz.lineark(True)
def test_berry_phase_fail_loop(self, setup):
g = setup.g.tile(2, 0).tile(2, 1).tile(2, 2)
H = Hamiltonian(g)
bz = BandStructure.param_circle(H,
20,
0.01, [0, 0, 1], [1 / 3] * 3,
loop=True)
elec.berry_phase(bz)
def test_bs_insert_jump(self):
g = geom.graphene()
nk = 10
bs = BandStructure(
g, [[0] * 3, [0.5, 0, 0], None, [0] * 3, None, [0., 0.5, 0]], nk,
['A', 'B', 'C', 'D'])
d = np.empty([nk])
d_jump = bs.insert_jump(d)
assert d_jump.shape == (nk + 2, )
d = np.empty([nk, 5])
d_jump = bs.insert_jump(d)
assert d_jump.shape == (nk + 2, 5)
assert np.isnan(d_jump).sum() == 10
d_jump = bs.insert_jump(d.T, value=np.inf)
assert d_jump.shape == (5, nk + 2)
assert np.isinf(d_jump).sum() == 10
def test_berry_phase(self, setup):
R, param = [0.1, 1.5], [1., 0.1]
g = setup.g.tile(2, 0).tile(2, 1).tile(2, 2)
H = Hamiltonian(g)
H.construct((R, param))
bz = BandStructure.param_circle(H, 20, 0.01, [0, 0, 1], [1 / 3] * 3)
berry_phase(bz)
berry_phase(bz, sub=0)
berry_phase(bz, eigvals=True, sub=0)
def test_bandstructure_pickle(self, setup):
import pickle as p
bz1 = BandStructure(setup.s1, [[0] * 2, [.5] * 2], 300, ['A', 'C'])
n = p.dumps(bz1)
bz2 = p.loads(n)
assert np.allclose(bz1.k, bz2.k)
assert np.allclose(bz1.weight, bz2.weight)
assert bz1.parent == bz2.parent
assert np.allclose(bz1.point, bz2.point)
assert np.allclose(bz1.division, bz2.division)
assert bz1.name == bz2.name
def finite_bands(dev, pot, SF):
H = Hamiltonian(dev)
R = np.array([1.4, 1.44, 3.33, 3.37]) * SF
t = (0, 3.16, 0, 0.39)
H.construct([R, t])
energies = pot.pot_func(dev.xyz)
for i in dev.iter():
H[i, i] = energies[i]
#band = BandStructure(H, [[-np.pi / 2.46, 0, 0], [np.pi / 2.46, 0, 0]],
# 400, [r'$-\pi$',r'$\pi$'])
band = BandStructure(
H, [[0, 0, 0], [0, 0.5, 0], [1 / 3, 2 / 3, 0], [0, 0, 0]], 400,
[r'$\Gamma$', r'$M$', r'$K$', r'$\Gamma$'])
bnds = band.asarray().eigh()
lk, kt, kl = band.lineark(True)
fig = plt.figure()
ax = fig.add_subplot(111)
for bnd in bnds.T:
ax.plot(lk, bnd)
plt.xticks(kt, kl)
plt.xlim(0, lk[-1])
#plt.ylim([0, 0.055])
plt.ylim([-3, 3])
#ax.set_ylim(-.1,.1)
plt.show()
def test_pbz2(self, setup):
bz = BandStructure(setup.s1, [[0] * 3, [.25] * 3, [.5] * 3], 300)
assert len(bz) == 300
def test_pbs_divisions(self, setup):
bz = BandStructure(setup.s1, [[0] * 3, [.25] * 3, [.5] * 3], [10, 10])
assert len(bz) == 21
def test_pbs_missing_arguments(self, setup):
with pytest.raises(ValueError):
bz = BandStructure(setup.s1, divisions=[10, 10])
def test_berry_phase_fail_sc(self, setup):
g = setup.g.tile(2, 0).tile(2, 1).tile(2, 2)
H = Hamiltonian(g)
bz = BandStructure.param_circle(H.geometry.sc, 20, 0.01, [0, 0, 1],
[1 / 3] * 3)
berry_phase(bz)
def test_pbs_deprecate_arguments(self, setup):
with pytest.deprecated_call():
bz = BandStructure(setup.s1, [[0] * 3, [.25] * 3, [.5] * 3],
division=[10, 10])
def test_bs_jump(self):
g = geom.graphene()
bs = BandStructure(g,
[[0] * 3, [0.5, 0, 0], None, [0] * 3, [0., 0.5, 0]],
30, ['A', 'B', 'C', 'D'])
assert len(bs) == 30
