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Modified sumk_dft to work also on real axis

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extract_G_loc(), total_density(), and calc_mu() support
        now real frequency data, which is necessary for DMFT
        when a real frequency impurity solver is used.
This commit is contained in:
Manuel Zingl 2016-04-20 19:01:29 +02:00
parent 7fe5f0222c
commit c5a9c9dfbb
1 changed files with 44 additions and 16 deletions
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60
python/sumk_dft.py
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@ -561,7 +561,7 @@ class SumkDFT:
for icrsh in range(self.n_corr_shells):
for bname,gf in SK_Sigma_imp[icrsh]: gf << self.rotloc(icrsh,gf,direction='toGlobal')
def extract_G_loc(self, mu=None, with_Sigma=True, with_dc=True):
def extract_G_loc(self, mu=None, iw_or_w='iw', with_Sigma=True, with_dc=True, broadening=None):
r"""
Extracts the local downfolded Green function by the Brillouin-zone integration of the lattice Green's function.
@ -573,6 +573,10 @@ class SumkDFT:
If True then the local GF is calculated with the self-energy self.Sigma_imp.
with_dc : boolean, optional
If True then the double-counting correction is subtracted from the self-energy in calculating the GF.
broadening : float, optional
Imaginary shift for the axis along which the real-axis GF is calculated.
If not provided, broadening will be set to double of the distance between mesh points in 'mesh'.
Only relevant for real-frequency GF.
Returns
-------
@ -583,19 +587,31 @@ class SumkDFT:
"""
if mu is None: mu = self.chemical_potential
G_loc = [ self.Sigma_imp_iw[icrsh].copy() for icrsh in range(self.n_corr_shells) ] # this list will be returned
if iw_or_w == "iw":
G_loc = [ self.Sigma_imp_iw[icrsh].copy() for icrsh in range(self.n_corr_shells) ] # this list will be returned
beta = G_loc[0].mesh.beta
G_loc_inequiv = [ BlockGf( name_block_generator = [ (block,GfImFreq(indices = inner, mesh = G_loc[0].mesh)) for block,inner in self.gf_struct_solver[ish].iteritems() ],
make_copies = False) for ish in range(self.n_inequiv_shells) ]
elif iw_or_w == "w":
G_loc = [ self.Sigma_imp_w[icrsh].copy() for icrsh in range(self.n_corr_shells) ] # this list will be returned
mesh = G_loc[0].mesh
G_loc_inequiv = [ BlockGf( name_block_generator = [ (block,GfReFreq(indices = inner, mesh = mesh)) for block,inner in self.gf_struct_solver[ish].iteritems() ],
make_copies = False) for ish in range(self.n_inequiv_shells) ]
for icrsh in range(self.n_corr_shells): G_loc[icrsh].zero() # initialize to zero
beta = G_loc[0].mesh.beta
ikarray = numpy.array(range(self.n_k))
for ik in mpi.slice_array(ikarray):
G_latt_iw = self.lattice_gf(ik=ik, mu=mu, iw_or_w="iw", with_Sigma=with_Sigma, with_dc=with_dc, beta=beta)
G_latt_iw *= self.bz_weights[ik]
if iw_or_w == 'iw':
G_latt = self.lattice_gf(ik=ik, mu=mu, iw_or_w=iw_or_w, with_Sigma=with_Sigma, with_dc=with_dc, beta=beta)
elif iw_or_w == 'w':
G_latt = self.lattice_gf(ik=ik, mu=mu, iw_or_w=iw_or_w, with_Sigma=with_Sigma, with_dc=with_dc, broadening=broadening, mesh=mesh)
G_latt *= self.bz_weights[ik]
for icrsh in range(self.n_corr_shells):
tmp = G_loc[icrsh].copy() # init temporary storage
for bname,gf in tmp: tmp[bname] << self.downfold(ik,icrsh,bname,G_latt_iw[bname],gf)
for bname,gf in tmp: tmp[bname] << self.downfold(ik,icrsh,bname,G_latt[bname],gf)
G_loc[icrsh] += tmp
# Collect data from mpi
@ -613,8 +629,6 @@ class SumkDFT:
for bname,gf in G_loc[icrsh]: G_loc[icrsh][bname] << self.rotloc(icrsh,gf,direction='toLocal')
# transform to CTQMC blocks:
G_loc_inequiv = [ BlockGf( name_block_generator = [ (block,GfImFreq(indices = inner, mesh = G_loc[0].mesh)) for block,inner in self.gf_struct_solver[ish].iteritems() ],
make_copies = False) for ish in range(self.n_inequiv_shells) ]
for ish in range(self.n_inequiv_shells):
for block,inner in self.gf_struct_solver[ish].iteritems():
for ind1 in inner:
@ -1072,14 +1086,14 @@ class SumkDFT:
for bl in degsh: gf_to_symm[bl] << ss
def total_density(self, mu=None, with_Sigma=True, with_dc=True):
def total_density(self, mu=None, iw_or_w="iw", with_Sigma=True, with_dc=True, broadening=None):
r"""
Calculates the total charge within the energy window for a given chemical potential.
The chemical potential is either given by parameter `mu` or, if it is not specified,
taken from `self.chemical_potential`.
The total charge is calculated from the trace of the GF in the Bloch basis.
By deafult, a full interacting GF is used. To use the non-interacting GF, set
By default, a full interacting GF is used. To use the non-interacting GF, set
parameter `with_Sigma = False`.
The number of bands within the energy windows generally depends on `k`. The trace is
@ -1088,7 +1102,7 @@ class SumkDFT:
Since in general n_orbitals depends on k, the calculation is done in the following order:
..math:: n_{tot} = \sum_{k} n(k),
with
..math:: n(k) = Tr G_{\nu\nu'}(k, i\omega_{n}).
..math:: n(k) = Tr G_{\nu\nu'}(k, i\omega_{n}).
The calculation is done in the global coordinate system, if distinction is made between local/global.
@ -1096,11 +1110,18 @@ class SumkDFT:
----------
mu : float, optional
Input chemical potential. If not specified, `self.chemical_potential` is used instead.
iw_or_w : string, optional
- `iw_or_w` = 'iw' for a imaginary-frequency self-energy
- `iw_or_w` = 'w' for a real-frequency self-energy
with_Sigma : boolean, optional
If `True` the full interacing GF is evaluated, otherwise the self-energy is not
included and the charge would correspond to a non-interacting system.
with_dc : boolean, optional
Whether or not to subtract the double-counting term from the self-energy.
broadening : float, optional
Imaginary shift for the axis along which the real-axis GF is calculated.
If not provided, broadening will be set to double of the distance between mesh points in 'mesh'.
Only relevant for real-frequency GF.
Returns
-------
@ -1112,8 +1133,8 @@ class SumkDFT:
dens = 0.0
ikarray = numpy.array(range(self.n_k))
for ik in mpi.slice_array(ikarray):
G_latt_iw = self.lattice_gf(ik=ik, mu=mu, iw_or_w="iw", with_Sigma=with_Sigma, with_dc=with_dc)
dens += self.bz_weights[ik] * G_latt_iw.total_density()
G_latt = self.lattice_gf(ik=ik, mu=mu, iw_or_w=iw_or_w, with_Sigma=with_Sigma, with_dc=with_dc, broadening=broadening)
dens += self.bz_weights[ik] * G_latt.total_density()
# collect data from mpi:
dens = mpi.all_reduce(mpi.world, dens, lambda x,y : x+y)
mpi.barrier()
@ -1134,7 +1155,7 @@ class SumkDFT:
self.chemical_potential = mu
def calc_mu(self, precision=0.01):
def calc_mu(self, precision=0.01, iw_or_w='iw',broadening=None):
r"""
Searches for the chemical potential that gives the DFT total charge.
A simple bisection method is used.
@ -1143,6 +1164,13 @@ class SumkDFT:
----------
precision : float, optional
A desired precision of the resulting total charge.
iw_or_w : string, optional
- `iw_or_w` = 'iw' for a imaginary-frequency self-energy
- `iw_or_w` = 'w' for a real-frequency self-energy
broadening : float, optional
Imaginary shift for the axis along which the real-axis GF is calculated.
If not provided, broadening will be set to double of the distance between mesh points in 'mesh'.
Only relevant for real-frequency GF.
Returns
-------
@ -1151,7 +1179,7 @@ class SumkDFT:
within specified precision.
"""
F = lambda mu : self.total_density(mu=mu)
F = lambda mu : self.total_density(mu=mu,iw_or_w=iw_or_w,broadening=broadening)
density = self.density_required - self.charge_below
self.chemical_potential = dichotomy.dichotomy(function = F,