Exemplo n.º 1
0
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
Exemplo n.º 2
0
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
Exemplo n.º 3
0
import numpy as np

# ----------------------------------------------------------------------

from pytriqs.operators import Operator
from pytriqs.archive import HDFArchive
from pyed.ParameterCollection import ParameterCollection
from pytriqs.gf import Gf, inverse, iOmega_n, InverseFourier

# ----------------------------------------------------------------------

from triqs_tprf.chi_from_gg2 import chi0_from_gg2_PH
from triqs_tprf.chi_from_gg2 import chi_from_gg2_PH

# ----------------------------------------------------------------------
if __name__ == '__main__':

    with HDFArchive('data_pomerol.h5', 'r') as A:
        p = A['p']

    p.chi0_nn = chi0_from_gg2_PH(p.g_iw['0'], p.g4_ph)
    p.chi_nn = chi_from_gg2_PH(p.g_iw['0'], p.g4_ph)

    chi = np.sum(p.chi_nn.data, axis=(0, 1, 2)) / p.beta**2

    np.testing.assert_array_almost_equal(chi.imag, np.zeros_like(chi.imag))
    p.chi = chi.real

    with HDFArchive('data_pomerol_chi.h5', 'w') as A:
        A['p'] = p
Exemplo n.º 4
0
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
Exemplo n.º 5
0
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
Exemplo n.º 6
0
from pytriqs.plot.mpl_interface import oplot, oplotr, oploti, plt     

from triqs_tprf.chi_from_gg2 import chi0_from_gg2_PH
from triqs_tprf.chi_from_gg2 import chi_from_gg2_PH

# ----------------------------------------------------------------------
if __name__ == '__main__':

    with HDFArchive('data_cthyb.h5', 'r') as A: 
        p = A['p']

    p.g_tau = g2_single_particle_transform(p.g_tau['0'], p.T)

    p.g_iw = GfImFreq(
        name=r'$g$', beta=p.beta,
        statistic='Fermion', n_points=400,
        target_shape=(4, 4))
    
    p.g_iw << Fourier(p.g_tau)

    p.g4_ph = g4_single_particle_transform(p.g4_ph, p.T)

    p.chi0_nn = chi0_from_gg2_PH(p.g_iw, p.g4_ph)
    p.chi_nn = chi_from_gg2_PH(p.g_iw, p.g4_ph)
    
    p.chi = np.sum(p.chi_nn.data, axis=(0, 1, 2)) / p.beta**2

    with HDFArchive('data_cthyb_chi.h5', 'w') as A: 
        A['p'] = p
Exemplo n.º 7
0
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
Exemplo n.º 8
0
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