From 1e591121d5aa47eb78e45ac5e4b786ce7c728be7 Mon Sep 17 00:00:00 2001
From: Junya Otsuki <otsuki@cmpt.phys.tohoku.ac.jp>
Date: Tue, 8 May 2018 11:38:48 +0900
Subject: [PATCH] Add a test of checking consistency bw G2_iw_freq_box() and
 G2_iw_freq_fix()

---
 test/python/CMakeLists.txt              |  1 +
 test/python/g2_freq_box_and_freq_fix.py | 87 +++++++++++++++++++++++++
 2 files changed, 88 insertions(+)
 create mode 100644 test/python/g2_freq_box_and_freq_fix.py

diff --git a/test/python/CMakeLists.txt b/test/python/CMakeLists.txt
index de8460f..1c9e136 100644
--- a/test/python/CMakeLists.txt
+++ b/test/python/CMakeLists.txt
@@ -7,6 +7,7 @@ file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/${all_h5_files} DESTINATION ${CMAKE_CURREN
 triqs_add_python_test(anderson_gf)
 triqs_add_python_test(slater_gf)
 triqs_add_python_test(wick)
+triqs_add_python_test(g2_freq_box_and_freq_fix)
 
 foreach(TEST_MPI_NUMPROC 1 2 4)
     triqs_add_python_test(anderson_g2_matsubara)
diff --git a/test/python/g2_freq_box_and_freq_fix.py b/test/python/g2_freq_box_and_freq_fix.py
new file mode 100644
index 0000000..883b6c5
--- /dev/null
+++ b/test/python/g2_freq_box_and_freq_fix.py
@@ -0,0 +1,87 @@
+from pytriqs.archive import HDFArchive
+from pytriqs.gf import *
+from pytriqs.operators import Operator, c, c_dag, n
+from pytriqs.utility import mpi
+from pytriqs.applications.impurity_solvers.pomerol2triqs import PomerolED
+from pytriqs.utility.comparison_tests import *
+import numpy as np
+from itertools import product
+
+# Single orbital Anderson model
+
+####################
+# Input parameters #
+####################
+
+beta = 10.0             # Inverse temperature
+U = 4.3                 # Coulomb repulsion
+mu = 1.1                # Chemical potential
+
+# Levels of the bath sites
+epsilon = [-1.5, 1.3]
+# Hopping amplitudes
+V = [0.52, 0.55]
+
+spin_names = ("up", "dn")
+
+# Number of bosonic Matsubara frequencies for G^2 calculations
+g2_n_wb = 3
+# Number of fermionic Matsubara frequencies for G^2 calculations
+g2_n_wf = 3
+
+# GF structure
+gf_struct = {'up' : [0], 'dn' : [0]}
+
+# Conversion from TRIQS to Pomerol notation for operator indices
+index_converter = {}
+index_converter.update({(sn, 0) : ("loc", 0, "down" if sn == "dn" else "up") for sn in spin_names})
+index_converter.update({("B%i_%s" % (k, sn), 0) : ("bath" + str(k), 0, "down" if sn == "dn" else "up")
+                        for k, sn in product(range(len(epsilon)), spin_names)})
+
+# Make PomerolED solver object
+ed = PomerolED(index_converter, verbose = True)
+
+# Number of particles on the impurity
+H_loc = -mu*(n('up', 0) + n('dn', 0)) + U * n('up', 0) * n('dn', 0)
+
+# Bath Hamiltonian
+H_bath = sum(eps*n("B%i_%s" % (k, sn), 0)
+             for sn, (k, eps) in product(spin_names, enumerate(epsilon)))
+
+# Hybridization Hamiltonian
+H_hyb = Operator()
+for k, v in enumerate(V):
+    H_hyb += sum(        v   * c_dag("B%i_%s" % (k, sn), 0) * c(sn, 0) +
+                 np.conj(v)  * c_dag(sn, 0) * c("B%i_%s" % (k, sn), 0)
+                 for sn in spin_names)
+
+# Complete Hamiltonian
+H = H_loc + H_hyb + H_bath
+
+# Diagonalize H
+ed.diagonalize(H)
+
+###########
+# G^{(2)} #
+###########
+
+common_g2_params = {'channel' : "PH",
+                    'gf_struct' : gf_struct,
+                    'beta' : beta,}
+
+four_indices = []
+four_indices.append( (('up',0), ('dn',0), ('dn',0), ('up',0)) )  # uddu
+
+# compute in a low-freq box
+G2_iw_freq_box = ed.G2_iw_freq_box( four_indices=four_indices, n_f=g2_n_wf, n_b=g2_n_wb, **common_g2_params )[0]
+print G2_iw_freq_box.shape
+
+# compute for fixed freqs
+three_freqs = [ (iwb, iwf1-g2_n_wf, iwf2-g2_n_wf) for iwb, iwf1, iwf2 in product( range(g2_n_wb), range(2*g2_n_wf), range(2*g2_n_wf) ) ]
+G2_iw_freq_fix = ed.G2_iw_freq_fix( four_indices=four_indices, three_freqs=three_freqs, **common_g2_params )[0]
+print G2_iw_freq_fix.shape
+# reshape from 1D array to 3D array
+G2_iw_freq_fix = np.reshape( G2_iw_freq_fix, (g2_n_wb, 2*g2_n_wf, 2*g2_n_wf) )
+print G2_iw_freq_fix.shape
+
+assert( np.allclose(G2_iw_freq_box, G2_iw_freq_fix) )