def solve_local_bse(chi0_wnn, chi_wnn):
r"""Solve the Bethe-Salpeter equation for the local vertex function
:math:`\Gamma_{abcd}(\omega, \nu, \nu')`.
Computes:
.. math::
\Gamma_{abcd}(\omega, \nu, \nu') = [\chi^{(0)}]^{-1} - \chi^{-1}
where the inverses are taken in the particle-hole channel pairing
of fermionic frequencies :math:`\nu` and :math:`\nu'` and orbital
indices.
Parameters
----------
chi0_wnn : Gerealized local bubble susceptibility
:math:`\chi^{(0)}_{abcd}(\omega, \nu, \nu')`
chi_wnn : Generalized local susceptibility
:math:`\chi_{abcd}(\omega, \nu, \nu')`
Returns
-------
gamma_wnn : Particle-hole vertex function
:math:`\Gamma_{abcd}(\omega, \nu, \nu')`
"""
gamma_wnn = inverse_PH(chi0_wnn) - inverse_PH(chi_wnn)
return gamma_wnn
def analytic_hubbard_atom(beta, U, nw, nwf, nwf_gf):
d = ParameterCollection()
d.beta, d.U, d.nw, d.nwf, d.nwf_gf = beta, U, nw, nwf, nwf_gf
g_iw = single_particle_greens_function(beta=beta, U=U, nw=nwf_gf)
d.G_iw = g_iw
# make block gf of the single gf
G_iw_block = BlockGf(name_list=['up', 'dn'], block_list=[g_iw, g_iw])
g_mat = block_iw_AB_to_matrix_valued(G_iw_block)
d.chi_m = chi_ph_magnetic(beta=beta, U=U, nw=nw, nwf=nwf)
d.chi0_m = chi0_from_gg2_PH(g_mat, d.chi_m)
# -- Numeric vertex from BSE
d.gamma_m_num = inverse_PH(d.chi0_m) - inverse_PH(d.chi_m)
# -- Analytic vertex
d.gamma_m = gamma_ph_magnetic(beta=beta, U=U, nw=nw, nwf=nwf)
# -- Analytic magnetization expecation value
# -- and static susceptibility
d.Z = 2. + 2 * np.exp(-beta * 0.5 * U)
d.m2 = 0.25 * (2 / d.Z)
d.chi_m_static = 2. * beta * d.m2
d.label = r'Analytic'
return d
def make_calc():
# ------------------------------------------------------------------
# -- Read precomputed ED data
filename = "data_pomerol.tar.gz"
p = read_TarGZ_HDFArchive(filename)
# ------------------------------------------------------------------
# -- RPA tensor
from triqs_tprf.rpa_tensor import get_rpa_tensor
from triqs_tprf.rpa_tensor import fundamental_operators_from_gf_struct
fundamental_operators = fundamental_operators_from_gf_struct(p.gf_struct)
p.U_abcd = get_rpa_tensor(p.H_int, fundamental_operators)
# ------------------------------------------------------------------
# -- Generalized PH susceptibility
loc_bse = ParameterCollection()
loc_bse.chi_wnn = chi_from_gg2_PH(p.G_iw, p.G2_iw_ph)
loc_bse.chi0_wnn = chi0_from_gg2_PH(p.G_iw, p.G2_iw_ph)
loc_bse.gamma_wnn = inverse_PH(loc_bse.chi0_wnn) - inverse_PH(
loc_bse.chi_wnn)
loc_bse.chi_wnn_ref = inverse_PH(
inverse_PH(loc_bse.chi0_wnn) - loc_bse.gamma_wnn)
np.testing.assert_array_almost_equal(loc_bse.chi_wnn.data,
loc_bse.chi_wnn_ref.data)
loc_bse.chi0_w = trace_nn(loc_bse.chi0_wnn)
loc_bse.chi_w = trace_nn(loc_bse.chi_wnn)
# ------------------------------------------------------------------
# -- RPA, using BSE inverses and constant Gamma
loc_rpa = ParameterCollection()
loc_rpa.U_abcd = p.U_abcd
# -- Build constant gamma
loc_rpa.gamma_wnn = loc_bse.gamma_wnn.copy()
loc_rpa.gamma_wnn.data[:] = loc_rpa.U_abcd[None, None, None, ...]
# Nb! In the three frequency form $\Gamma \propto U/\beta^2$
loc_rpa.gamma_wnn.data[:] /= p.beta**2
loc_rpa.chi0_wnn = loc_bse.chi0_wnn
loc_rpa.chi0_w = loc_bse.chi0_w
# -- Solve RPA
loc_rpa.chi_wnn = inverse_PH(
inverse_PH(loc_rpa.chi0_wnn) - loc_rpa.gamma_wnn)
loc_rpa.chi_w = trace_nn(loc_rpa.chi_wnn)
# ------------------------------------------------------------------
# -- Bubble RPA on lattice
lat_rpa = ParameterCollection()
# -- Setup dummy lattice Green's function equal to local Green's function
bz = BrillouinZone(
BravaisLattice(units=np.eye(3), orbital_positions=[(0, 0, 0)]))
periodization_matrix = np.diag(np.array(list([1] * 3), dtype=np.int32))
kmesh = MeshBrillouinZone(bz, periodization_matrix)
wmesh = MeshImFreq(beta=p.beta, S='Fermion', n_max=p.nwf_gf)
lat_rpa.g_wk = Gf(mesh=MeshProduct(wmesh, kmesh),
target_shape=p.G_iw.target_shape)
lat_rpa.g_wk[:, Idx(0, 0, 0)] = p.G_iw
# -- chi0_wk bubble and chi_wk_rpa bubble RPA
from triqs_tprf.lattice_utils import imtime_bubble_chi0_wk
lat_rpa.chi0_wk = imtime_bubble_chi0_wk(lat_rpa.g_wk, nw=1)
from triqs_tprf.lattice import solve_rpa_PH
lat_rpa.chi_wk = solve_rpa_PH(lat_rpa.chi0_wk, p.U_abcd)
lat_rpa.chi0_w = lat_rpa.chi0_wk[:, Idx(0, 0, 0)]
lat_rpa.chi_w = lat_rpa.chi_wk[:, Idx(0, 0, 0)]
print '--> cf Tr[chi0] and chi0_wk'
print loc_rpa.chi0_w.data.reshape((4, 4)).real
print lat_rpa.chi0_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(loc_rpa.chi0_w.data,
lat_rpa.chi0_w.data,
decimal=2)
print 'ok!'
print '--> cf Tr[chi_rpa] and chi_wk_rpa'
print loc_rpa.chi_w.data.reshape((4, 4)).real
print lat_rpa.chi_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(loc_rpa.chi_w.data,
lat_rpa.chi_w.data,
decimal=2)
print 'ok!'
# ------------------------------------------------------------------
# -- Lattice BSE
lat_bse = ParameterCollection()
lat_bse.g_wk = lat_rpa.g_wk
from triqs_tprf.lattice import fourier_wk_to_wr
lat_bse.g_wr = fourier_wk_to_wr(lat_bse.g_wk)
from triqs_tprf.lattice import chi0r_from_gr_PH
lat_bse.chi0_wnr = chi0r_from_gr_PH(nw=1, nnu=p.nwf, gr=lat_bse.g_wr)
from triqs_tprf.lattice import chi0q_from_chi0r
lat_bse.chi0_wnk = chi0q_from_chi0r(lat_bse.chi0_wnr)
# -- Lattice BSE calc
from triqs_tprf.lattice import chiq_from_chi0q_and_gamma_PH
lat_bse.chi_kwnn = chiq_from_chi0q_and_gamma_PH(lat_bse.chi0_wnk,
loc_bse.gamma_wnn)
# -- Trace results
from triqs_tprf.lattice import chi0q_sum_nu_tail_corr_PH
from triqs_tprf.lattice import chi0q_sum_nu
lat_bse.chi0_wk_tail_corr = chi0q_sum_nu_tail_corr_PH(lat_bse.chi0_wnk)
lat_bse.chi0_wk = chi0q_sum_nu(lat_bse.chi0_wnk)
from triqs_tprf.lattice import chiq_sum_nu, chiq_sum_nu_q
lat_bse.chi_kw = chiq_sum_nu(lat_bse.chi_kwnn)
lat_bse.chi0_w_tail_corr = lat_bse.chi0_wk_tail_corr[:, Idx(0, 0, 0)]
lat_bse.chi0_w = lat_bse.chi0_wk[:, Idx(0, 0, 0)]
lat_bse.chi_w = lat_bse.chi_kw[Idx(0, 0, 0), :]
print '--> cf Tr[chi0_wnk] and chi0_wk'
print lat_bse.chi0_w_tail_corr.data.reshape((4, 4)).real
print lat_bse.chi0_w.data.reshape((4, 4)).real
print lat_rpa.chi0_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(lat_bse.chi0_w_tail_corr.data,
lat_rpa.chi0_w.data)
np.testing.assert_array_almost_equal(lat_bse.chi0_w.data,
lat_rpa.chi0_w.data,
decimal=2)
print 'ok!'
print '--> cf Tr[chi_kwnn] and chi_wk'
print lat_bse.chi_w.data.reshape((4, 4)).real
print loc_bse.chi_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(lat_bse.chi_w.data,
loc_bse.chi_w.data)
print 'ok!'
# ------------------------------------------------------------------
# -- Store to hdf5
filename = 'data_bse_rpa.h5'
with HDFArchive(filename, 'w') as res:
res['p'] = p
def solve_local_bse(chi0_wnn, chi_wnn):
gamma_wnn = inverse_PH(chi0_wnn) - inverse_PH(chi_wnn)
return gamma_wnn
def analytic_hubbard_atom(beta, U, nw, nwf, nwf_gf):
r""" Compute dynamical response functions for the Hubbard atom at half filling.
This function returns an object that contains the single-particle
Greens function :math:`G(\omega)`, the magnetic two-particle generalized susceptibility
:math:`\chi_m(\omega, \nu, \nu')`, and the corresponding bare bubble
:math:`\chi^{(0)}_m(\omega, \nu, \nu')`, and the magnetic vertex function
:math:`\Gamma_m(\omega, \nu, \nu')`.
This is implemented using analytical formulas from
Thunstrom et al. [PRB 98, 235107 (2018)]
please cite the paper if you use this function!
In particular this is one exact solution to the Bethe-Salpeter
equation, that is the infinite matrix inverse problem:
.. math::
\Gamma_m = [\chi^{(0)}_m]^{-1} - \chi_m^{-1}
Parameters
----------
beta : float
Inverse temperature.
U : float
Hubbard U interaction parameter.
nw : int
Number of bosonic Matsubara frequencies
in the computed two-particle response functions.
nwf : int
Number of fermionic Matsubara frequencies
in the computed two-particle response functions.
nwf_gf : int
Number of fermionic Matsubara frequencies
in the computed single-particle Greens function.
Returns
-------
p : ParameterCollection
Object containing all the response functions and some other
observables, `p.G_iw`, `p.chi_m`, `p.chi0_m`,
`p.gamma_m`, `p.Z`, `p.m2`, `p.chi_m_static`.
"""
d = ParameterCollection()
d.beta, d.U, d.nw, d.nwf, d.nwf_gf = beta, U, nw, nwf, nwf_gf
g_iw = single_particle_greens_function(beta=beta, U=U, nw=nwf_gf)
d.G_iw = g_iw
# make block gf of the single gf
G_iw_block = BlockGf(name_list=['up', 'dn'], block_list=[g_iw, g_iw])
g_mat = block_iw_AB_to_matrix_valued(G_iw_block)
d.chi_m = chi_ph_magnetic(beta=beta, U=U, nw=nw, nwf=nwf)
d.chi0_m = chi0_from_gg2_PH(g_mat, d.chi_m)
# -- Numeric vertex from BSE
d.gamma_m_num = inverse_PH(d.chi0_m) - inverse_PH(d.chi_m)
# -- Analytic vertex
d.gamma_m = gamma_ph_magnetic(beta=beta, U=U, nw=nw, nwf=nwf)
# -- Analytic magnetization expecation value
# -- and static susceptibility
d.Z = 2. + 2 * np.exp(-beta * 0.5 * U)
d.m2 = 0.25 * (2 / d.Z)
d.chi_m_static = 2. * beta * d.m2
d.label = r'Analytic'
return d
p = mpi.bcast(p)
# -- Sample G2
p.solve.n_cycles = int(1e9 / 40.)
p.solve.measure_G_l = False
p.solve.measure_G_tau = False
p.solve.measure_G2_iw_ph = True
p.solve.measure_G2_blocks = set([('up', 'up'), ('up', 'do')])
p.solve.measure_G2_n_bosonic = 1
p.solve.measure_G2_n_fermionic = 20
cthyb = triqs_cthyb.Solver(**p.init.dict())
cthyb.G0_iw << p.G0_w
cthyb.solve(**p.solve.dict())
p.G2_iw_ph = cthyb.G2_iw_ph.copy()
# -- Compute DMFT impurity vertex
from triqs_tprf.linalg import inverse_PH
from triqs_tprf.chi_from_gg2 import chi0_from_gg2_PH
p.chi_m = p.G2_iw_ph[('up', 'up')] - p.G2_iw_ph[('up', 'do')]
p.chi0_m = chi0_from_gg2_PH(p.G_w['up'], p.chi_m)
p.gamma_m = inverse_PH(p.chi0_m) - inverse_PH(p.chi_m)
del p.solve.measure_G2_blocks
if mpi.is_master_node():
with HDFArchive('data_g2.h5', 'w') as a:
a['p'] = p
def make_calc():
# ------------------------------------------------------------------
# -- Read precomputed ED data
filename = "bse_and_rpa_loc_vs_latt.tar.gz"
p = read_TarGZ_HDFArchive(filename)['p']
# ------------------------------------------------------------------
# -- RPA tensor
from triqs_tprf.rpa_tensor import get_rpa_tensor
from triqs_tprf.rpa_tensor import fundamental_operators_from_gf_struct
fundamental_operators = fundamental_operators_from_gf_struct(p.gf_struct)
p.U_abcd = get_rpa_tensor(p.H_int, fundamental_operators)
# ------------------------------------------------------------------
# -- Generalized PH susceptibility
loc_bse = ParameterCollection()
loc_bse.chi_wnn = chi_from_gg2_PH(p.G_iw, p.G2_iw_ph)
loc_bse.chi0_wnn = chi0_from_gg2_PH(p.G_iw, p.G2_iw_ph)
loc_bse.gamma_wnn = inverse_PH(loc_bse.chi0_wnn) - inverse_PH(
loc_bse.chi_wnn)
loc_bse.chi_wnn_ref = inverse_PH(
inverse_PH(loc_bse.chi0_wnn) - loc_bse.gamma_wnn)
np.testing.assert_array_almost_equal(loc_bse.chi_wnn.data,
loc_bse.chi_wnn_ref.data)
from triqs_tprf.bse import solve_local_bse
loc_bse.gamma_wnn_ref = solve_local_bse(loc_bse.chi0_wnn, loc_bse.chi_wnn)
np.testing.assert_array_almost_equal(loc_bse.gamma_wnn.data,
loc_bse.gamma_wnn_ref.data)
loc_bse.chi0_w = trace_nn(loc_bse.chi0_wnn)
loc_bse.chi_w = trace_nn(loc_bse.chi_wnn)
# ------------------------------------------------------------------
# -- RPA, using BSE inverses and constant Gamma
loc_rpa = ParameterCollection()
loc_rpa.chi0_wnn = loc_bse.chi0_wnn
loc_rpa.chi0_w = loc_bse.chi0_w
loc_rpa.U_abcd = p.U_abcd
# -- Build constant gamma
from triqs_tprf.rpa_tensor import get_gamma_rpa
loc_rpa.gamma_wnn = get_gamma_rpa(loc_rpa.chi0_wnn, loc_rpa.U_abcd)
# -- Solve RPA
loc_rpa.chi_wnn = inverse_PH(
inverse_PH(loc_rpa.chi0_wnn) - loc_rpa.gamma_wnn)
loc_rpa.chi_w = trace_nn(loc_rpa.chi_wnn)
# ------------------------------------------------------------------
# -- Bubble RPA on lattice
lat_rpa = ParameterCollection()
# -- Setup dummy lattice Green's function equal to local Green's function
bz = BrillouinZone(
BravaisLattice(units=np.eye(3), orbital_positions=[(0, 0, 0)]))
periodization_matrix = np.diag(np.array(list([1] * 3), dtype=np.int32))
kmesh = MeshBrillouinZone(bz, periodization_matrix)
wmesh = MeshImFreq(beta=p.beta, S='Fermion', n_max=p.nwf_gf)
lat_rpa.g_wk = Gf(mesh=MeshProduct(wmesh, kmesh),
target_shape=p.G_iw.target_shape)
lat_rpa.g_wk[:, Idx(0, 0, 0)] = p.G_iw
# -- chi0_wk bubble and chi_wk_rpa bubble RPA
from triqs_tprf.lattice_utils import imtime_bubble_chi0_wk
lat_rpa.chi0_wk = imtime_bubble_chi0_wk(lat_rpa.g_wk, nw=1)
from triqs_tprf.lattice import solve_rpa_PH
lat_rpa.chi_wk = solve_rpa_PH(lat_rpa.chi0_wk, p.U_abcd)
lat_rpa.chi0_w = lat_rpa.chi0_wk[:, Idx(0, 0, 0)]
lat_rpa.chi_w = lat_rpa.chi_wk[:, Idx(0, 0, 0)]
print '--> cf Tr[chi0] and chi0_wk'
print loc_rpa.chi0_w.data.reshape((4, 4)).real
print lat_rpa.chi0_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(loc_rpa.chi0_w.data,
lat_rpa.chi0_w.data,
decimal=2)
print 'ok!'
print '--> cf Tr[chi_rpa] and chi_wk_rpa'
print loc_rpa.chi_w.data.reshape((4, 4)).real
print lat_rpa.chi_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(loc_rpa.chi_w.data,
lat_rpa.chi_w.data,
decimal=2)
print 'ok!'
# ------------------------------------------------------------------
# -- Lattice BSE
lat_bse = ParameterCollection()
lat_bse.g_wk = lat_rpa.g_wk
lat_bse.mu = p.mu
lat_bse.e_k = Gf(mesh=kmesh, target_shape=p.G_iw.target_shape)
lat_bse.e_k[Idx(0, 0, 0)] = np.eye(2)
lat_bse.sigma_w = p.G_iw.copy()
lat_bse.sigma_w << iOmega_n + lat_bse.mu * np.eye(2) - lat_bse.e_k[Idx(
0, 0, 0)] - inverse(p.G_iw)
lat_bse.g_wk_ref = lat_bse.g_wk.copy()
lat_bse.g_wk_ref[:, Idx(0, 0, 0)] << inverse(iOmega_n +
lat_bse.mu * np.eye(2) -
lat_bse.e_k[Idx(0, 0, 0)] -
lat_bse.sigma_w)
np.testing.assert_array_almost_equal(lat_bse.g_wk.data,
lat_bse.g_wk_ref.data)
#for w in lat_bse.g_wk.mesh.components[0]:
# print w, lat_bse.g_wk[w, Idx(0,0,0)][0, 0]
from triqs_tprf.lattice import fourier_wk_to_wr
lat_bse.g_wr = fourier_wk_to_wr(lat_bse.g_wk)
from triqs_tprf.lattice import chi0r_from_gr_PH
lat_bse.chi0_wnr = chi0r_from_gr_PH(nw=1, nn=p.nwf, g_nr=lat_bse.g_wr)
from triqs_tprf.lattice import chi0q_from_chi0r
lat_bse.chi0_wnk = chi0q_from_chi0r(lat_bse.chi0_wnr)
#for n in lat_bse.chi0_wnk.mesh.components[1]:
# print n.value, lat_bse.chi0_wnk[Idx(0), n, Idx(0,0,0)][0,0,0,0]
# -- Lattice BSE calc
from triqs_tprf.lattice import chiq_from_chi0q_and_gamma_PH
lat_bse.chi_kwnn = chiq_from_chi0q_and_gamma_PH(lat_bse.chi0_wnk,
loc_bse.gamma_wnn)
# -- Lattice BSE calc with built in trace
from triqs_tprf.lattice import chiq_sum_nu_from_chi0q_and_gamma_PH
lat_bse.chi_kw_ref = chiq_sum_nu_from_chi0q_and_gamma_PH(
lat_bse.chi0_wnk, loc_bse.gamma_wnn)
# -- Lattice BSE calc with built in trace using g_wk
from triqs_tprf.lattice import chiq_sum_nu_from_g_wk_and_gamma_PH
lat_bse.chi_kw_tail_corr_ref = chiq_sum_nu_from_g_wk_and_gamma_PH(
lat_bse.g_wk, loc_bse.gamma_wnn)
# -- Trace results
from triqs_tprf.lattice import chi0q_sum_nu_tail_corr_PH
from triqs_tprf.lattice import chi0q_sum_nu
lat_bse.chi0_wk_tail_corr = chi0q_sum_nu_tail_corr_PH(lat_bse.chi0_wnk)
lat_bse.chi0_wk = chi0q_sum_nu(lat_bse.chi0_wnk)
from triqs_tprf.lattice import chiq_sum_nu, chiq_sum_nu_q
lat_bse.chi_kw = chiq_sum_nu(lat_bse.chi_kwnn)
np.testing.assert_array_almost_equal(lat_bse.chi_kw.data,
lat_bse.chi_kw_ref.data)
from triqs_tprf.bse import solve_lattice_bse
lat_bse.chi_kw_tail_corr, tmp = solve_lattice_bse(lat_bse.g_wk,
loc_bse.gamma_wnn)
from triqs_tprf.bse import solve_lattice_bse_e_k_sigma_w
lat_bse.chi_kw_tail_corr_new = solve_lattice_bse_e_k_sigma_w(
lat_bse.mu, lat_bse.e_k, lat_bse.sigma_w, loc_bse.gamma_wnn)
np.testing.assert_array_almost_equal(lat_bse.chi_kw_tail_corr.data,
lat_bse.chi_kw_tail_corr_ref.data)
np.testing.assert_array_almost_equal(lat_bse.chi_kw_tail_corr.data,
lat_bse.chi_kw_tail_corr_new.data)
np.testing.assert_array_almost_equal(lat_bse.chi_kw_tail_corr_ref.data,
lat_bse.chi_kw_tail_corr_new.data)
lat_bse.chi0_w_tail_corr = lat_bse.chi0_wk_tail_corr[:, Idx(0, 0, 0)]
lat_bse.chi0_w = lat_bse.chi0_wk[:, Idx(0, 0, 0)]
lat_bse.chi_w_tail_corr = lat_bse.chi_kw_tail_corr[Idx(0, 0, 0), :]
lat_bse.chi_w = lat_bse.chi_kw[Idx(0, 0, 0), :]
print '--> cf Tr[chi0_wnk] and chi0_wk'
print lat_bse.chi0_w_tail_corr.data.reshape((4, 4)).real
print lat_bse.chi0_w.data.reshape((4, 4)).real
print lat_rpa.chi0_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(lat_bse.chi0_w_tail_corr.data,
lat_rpa.chi0_w.data)
np.testing.assert_array_almost_equal(lat_bse.chi0_w.data,
lat_rpa.chi0_w.data,
decimal=2)
print 'ok!'
print '--> cf Tr[chi_kwnn] and chi_wk (without chi0 tail corr)'
print lat_bse.chi_w.data.reshape((4, 4)).real
print loc_bse.chi_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(lat_bse.chi_w.data,
loc_bse.chi_w.data)
print 'ok!'
# ------------------------------------------------------------------
# -- Use chi0 tail corrected trace to correct chi_rpa cf bubble
dchi_wk = lat_bse.chi0_wk_tail_corr - lat_bse.chi0_wk
dchi_w = dchi_wk[:, Idx(0, 0, 0)]
loc_rpa.chi_w_tail_corr = loc_rpa.chi_w + dchi_w
# -- this will be the same, but it will be close to the real physical value
lat_bse.chi_w_tail_corr_ref = lat_bse.chi_w + dchi_w
loc_bse.chi_w_tail_corr_ref = loc_bse.chi_w + dchi_w
print '--> cf Tr[chi_rpa] and chi_wk_rpa'
print loc_rpa.chi_w.data.reshape((4, 4)).real
print loc_rpa.chi_w_tail_corr.data.reshape((4, 4)).real
print lat_rpa.chi_w.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(loc_rpa.chi_w_tail_corr.data,
lat_rpa.chi_w.data,
decimal=3)
print '--> cf Tr[chi_kwnn] with tail corr (from chi0_wnk)'
print lat_bse.chi_w_tail_corr.data.reshape((4, 4)).real
print lat_bse.chi_w_tail_corr_ref.data.reshape((4, 4)).real
np.testing.assert_array_almost_equal(lat_bse.chi_w_tail_corr.data,
lat_bse.chi_w_tail_corr_ref.data)
print 'ok!'
# ------------------------------------------------------------------
# -- Store to hdf5
filename = 'data_bse_rpa.h5'
with HDFArchive(filename, 'w') as res:
res['p'] = p
def make_calc():
# ------------------------------------------------------------------
# -- Hubbard atom with two bath sites, Hamiltonian
p = ParameterCollection(
beta=1.0,
U=5.0,
nw=1,
nwf=20,
)
p.nwf_gf = 4 * p.nwf
p.mu = 0.5 * p.U
# ------------------------------------------------------------------
ca_up, cc_up = c('0', 0), c_dag('0', 0)
ca_do, cc_do = c('0', 1), c_dag('0', 1)
docc = cc_up * ca_up * cc_do * ca_do
nA = cc_up * ca_up + cc_do * ca_do
p.H = -p.mu * nA + p.U * docc
# ------------------------------------------------------------------
# -- Exact diagonalization
# Conversion from TRIQS to Pomerol notation for operator indices
# TRIQS: block_name, inner_index
# Pomerol: site_label, orbital_index, spin_name
index_converter = {
('0', 0): ('loc', 0, 'up'),
('0', 1): ('loc', 0, 'down'),
}
# -- Create Exact Diagonalization instance
ed = PomerolED(index_converter, verbose=True)
ed.diagonalize(p.H) # -- Diagonalize H
gf_struct = [['0', [0, 1]]]
# -- Single-particle Green's functions
p.G_iw = ed.G_iw(gf_struct, p.beta, n_iw=p.nwf_gf)['0']
# -- Particle-particle two-particle Matsubara frequency Green's function
opt = dict(beta=p.beta,
gf_struct=gf_struct,
blocks=set([("0", "0")]),
n_iw=p.nw,
n_inu=p.nwf)
p.G2_iw_ph = ed.G2_iw_inu_inup(channel='PH', **opt)[('0', '0')]
# ------------------------------------------------------------------
# -- Generalized susceptibility in magnetic PH channel
p.chi_m = Gf(mesh=p.G2_iw_ph.mesh, target_shape=[1, 1, 1, 1])
p.chi_m[0, 0, 0, 0] = p.G2_iw_ph[0, 0, 0, 0] - p.G2_iw_ph[0, 0, 1, 1]
p.chi0_m = chi0_from_gg2_PH(p.G_iw, p.chi_m)
p.label = r'Pomerol'
# ------------------------------------------------------------------
# -- Generalized susceptibility in PH channel
p.chi = chi_from_gg2_PH(p.G_iw, p.G2_iw_ph)
p.chi0 = chi0_from_gg2_PH(p.G_iw, p.G2_iw_ph)
p.gamma = inverse_PH(p.chi0) - inverse_PH(p.chi)
# ------------------------------------------------------------------
# -- Store to hdf5
filename = 'data_pomerol.h5'
with HDFArchive(filename, 'w') as res:
res['p'] = p