occ = [
ed.ensemble_average(i, i, beta).real
for i in product(spin_names, orb_names)
]
# Compute G(i\omega)
G_iw = ed.G_iw(gf_struct, beta, n_iw)
# Compute G(\tau)
G_tau = ed.G_tau(gf_struct, beta, n_tau)
# Compute G(\omega)
G_w = ed.G_w(gf_struct, beta, energy_window, n_w, 0.01)
# Compute \chi(\tau) = <n_{up,0}(\tau) n_{dn,0}(0)>
chi_tau = ed.chi_tau(('up', 0), ('up', 0), ('dn', 0), ('dn', 0), beta, n_tau)
# Compute \chi(i\nu)
chi_inu = ed.chi_inu(('up', 0), ('up', 0), ('dn', 0), ('dn', 0), beta, n_iw)
# Compute \chi_c(\tau) = <n_{up,0}(\tau) n_{dn,0}(0)> - <n_{up,0}><n_{dn,0}>
chi_tau_c = ed.chi_tau(('up', 0), ('up', 0), ('dn', 0), ('dn', 0), beta, n_tau,
True)
# Compute \chi_c(i\nu)
chi_inu_c = ed.chi_inu(('up', 0), ('up', 0), ('dn', 0), ('dn', 0), beta, n_iw,
True)
###########
# G^{(2)} #
###########
zero_freq = abs(complex(inu)) < 1e-10
chi_up_up_ref = (w[1] + w[3]) * (1 - w[1] -
w[3]) * beta if zero_freq else 0
assert abs(chi_up_up[inu] - chi_up_up_ref) < 1e-10
chi_up_dn_ref = (w[3] - (w[1] + w[3]) *
(w[2] + w[3])) * beta if zero_freq else 0
assert abs(chi_up_dn[inu] - chi_up_dn_ref) < 1e-10
if h_field == 0:
chi_Sp_Sm_ref = w[1] * beta if zero_freq else 0
else:
chi_Sp_Sm_ref = -(w[1] - w[2]) / (inu - 2 * h_field)
assert abs(chi_Sp_Sm[inu] - chi_Sp_Sm_ref) < 1e-10
# Number of time slices for susceptibility calculation
n_tau = 200
chi_up_up = ed.chi_tau(('up', 0), ('up', 0), ('up', 0), ('up', 0), beta, n_tau,
True)
chi_up_dn = ed.chi_tau(('up', 0), ('up', 0), ('dn', 0), ('dn', 0), beta, n_tau,
True)
for tau in chi_up_up.mesh:
chi_up_up_ref = (w[1] + w[3]) * (1 - w[1] - w[3])
assert abs(chi_up_up[tau] - chi_up_up_ref) < 1e-10
chi_up_dn_ref = (w[3] - (w[1] + w[3]) * (w[2] + w[3]))
assert abs(chi_up_dn[tau] - chi_up_dn_ref) < 1e-10