mirror of
https://github.com/triqs/dft_tools
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60 lines
1.7 KiB
Python
60 lines
1.7 KiB
Python
import numpy
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from pytriqs.gf.local import *
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class Solver:
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"""A simple IPT solver for the symmetric one band Anderson model"""
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def __init__(self, **params):
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self.name = 'Iterated Perturbation Theory'
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self.U = params['U']
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self.beta = params['beta']
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# Only one block in GFs
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g = GfImFreq(indices =[0], beta =self.beta, name ='0')
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self.G = BlockGf(name_list=('0',), block_list=(g,))
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self.G0 = self.G.copy()
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def Solve(self):
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# Imaginary time representation of G_0
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g0t = GfImTime(indices =[0], beta =self.beta, name ='0')
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G0t = BlockGf(name_list=('0',), block_list=(g0t,))
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G0t['0'].set_from_inverse_fourier(self.G0['0'])
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# IPT expression for the self-energy (particle-holy symmetric case is implied)
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Sigmat = G0t.copy()
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Sigmat['0'] <<= (self.U**2)*G0t['0']*G0t['0']*G0t['0']
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self.Sigma = self.G0.copy()
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self.Sigma['0'].set_from_fourier(Sigmat['0'])
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# New impurity GF from the Dyson's equation
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self.G <<= self.G0*inverse(1.0 - self.Sigma*self.G0)
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S = 0
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def run(**params):
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"""IPT loop"""
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# Read input parameters
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U = params['U']
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beta = params['beta']
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N_loops = params['N_loops']
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Initial_G0 = params['Initial_G0']
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Self_Consistency = params['Self_Consistency']
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global S
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# Create a new IPT solver object
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S = Solver(U=U, beta=beta)
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# Initialize the bare GF using the function passed in through Initial_G0 parameter
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Initial_G0(S.G0)
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# DMFT iterations
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for IterationNumber in range(N_loops):
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print "DMFT iteration number ", IterationNumber
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S.Solve()
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Self_Consistency(S.G0,S.G)
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