mirror of
https://github.com/triqs/dft_tools
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60 lines
1.9 KiB
Python
60 lines
1.9 KiB
Python
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################################################################################
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#
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# TRIQS: a Toolbox for Research in Interacting Quantum Systems
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#
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# Copyright (C) 2011 by M. Ferrero, O. Parcollet
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#
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# TRIQS is free software: you can redistribute it and/or modify it under the
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# terms of the GNU General Public License as published by the Free Software
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# Foundation, either version 3 of the License, or (at your option) any later
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# version.
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#
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# TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
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# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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# details.
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#
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# You should have received a copy of the GNU General Public License along with
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# TRIQS. If not, see <http://www.gnu.org/licenses/>.
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#
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################################################################################
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from numpy import array, arange
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from math import pi
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from cmath import sqrt, log
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from pytriqs.gf.local import GfImFreq, GfReFreq
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from pytriqs.gf.local.descriptors import Function
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beta = 100 # Inverse temperature
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L = 10 # Number of Matsubara frequencies used in the Pade approximation
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eta = 0.01 # Imaginary frequency shift
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## Test Green's functions ##
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# Two Lorentzians
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def GLorentz(z):
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return 0.7/(z-2.6+0.3*1j) + 0.3/(z+3.4+0.1*1j)
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# Semicircle
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def GSC(z):
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return 2.0*(z + sqrt(1-z**2)*(log(1-z) - log(-1+z))/pi)
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# A superposition of GLorentz(z) and GSC(z) with equal weights
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def G(z):
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return 0.5*GLorentz(z) + 0.5*GSC(z)
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# Matsubara GF
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gm = GfImFreq(indices = [0], beta = beta, name = "gm")
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gm <<= Function(G)
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gm.tail.zero()
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gm.tail[1] = array([[1.0]])
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# Analytic continuation of gm
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g_pade = GfReFreq(indices = [0], window = (-5.995, 5.995), n_points = 1200, name = "g_pade")
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g_pade.set_from_pade(gm, n_points = L, freq_offset = eta)
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from pytriqs.archive import HDFArchive
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R = HDFArchive('pade.output.h5','w')
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R['g_pade'] = g_pade
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