Fixed imtime_bubble_chi0_wk not returning chi on a symmetrized DLR me…

…sh if Gf in argument has a symmetrized DLR mesh

c++/triqs_tprf/lattice/chi_imtime.cpp

@@ -35,7 +35,7 @@ namespace triqs_tprf {
 // ----------------------------------------------------
 // chi0 bubble in DLR imaginary time
 
-chi_Dtr_t chi0_tr_from_grt_PH(g_Dtr_cvt g_tr) {
+chi_Dtr_t chi0_tr_from_grt_PH(g_Dtr_cvt g_tr, bool symmetrize) {
 
   auto _ = all_t{};
 
@@ -45,7 +45,7 @@ chi_Dtr_t chi0_tr_from_grt_PH(g_Dtr_cvt g_tr) {
   int nb = g_tr.target().shape()[0];
   double beta = tmesh.beta();
 
-  dlr_imtime btmesh{beta, Boson, tmesh.w_max(), tmesh.eps()};
+  dlr_imtime btmesh{beta, Boson, tmesh.w_max(), tmesh.eps(), symmetrize};
   chi_Dtr_t chi0_tr{{btmesh, rmesh}, {nb, nb, nb, nb}};
 
   auto g_target = g_tr.target();

c++/triqs_tprf/lattice/chi_imtime.hpp

@@ -36,7 +36,7 @@ namespace triqs_tprf {
   @return Generalized susceptibility :math:`\chi^{(0)}_{\bar{a}b\bar{c}d}(\tau, \mathbf{r})` in imaginary time and real-space.
  */
 chi_tr_t chi0_tr_from_grt_PH(g_tr_cvt g_tr);
-chi_Dtr_t chi0_tr_from_grt_PH(g_Dtr_cvt g_tr);
+chi_Dtr_t chi0_tr_from_grt_PH(g_Dtr_cvt g_tr, bool symmetrize=false);
 chi_wr_t chi0_wr_from_grt_PH(g_tr_cvt g_tr, int nw);
 
 /** Generalized susceptibility zero imaginary frequency bubble in the particle-hole channel :math:`\chi^{(0)}_{\bar{a}b\bar{c}d}(\omega=0, \mathbf{r})`

python/triqs_tprf/lattice_desc.py

@@ -1339,7 +1339,7 @@
 out
      Generalized susceptibility :math:`\chi^{(0)}_{\bar{a}b\bar{c}d}(\tau, \mathbf{r})` in imaginary time and real-space.""")
 
-module.add_function ("triqs_tprf::chi_Dtr_t triqs_tprf::chi0_tr_from_grt_PH (triqs_tprf::g_Dtr_cvt g_tr)")
+module.add_function ("triqs_tprf::chi_Dtr_t triqs_tprf::chi0_tr_from_grt_PH (triqs_tprf::g_Dtr_cvt g_tr, bool symmetrize=false)")
 
 module.add_function ("std::tuple<triqs_tprf::g_Tk_t, triqs_tprf::g_Tk_t> triqs_tprf::g0_Tk_les_gtr_from_e_k(triqs_tprf::e_k_cvt e_k, triqs::mesh::retime Tmesh, double beta)")
 

python/triqs_tprf/lattice_utils.py

@@ -200,6 +200,11 @@ def imtime_bubble_chi0_wk(g_wk, nw=1, save_memory=False, verbose=True):
 
     ntau = 2 * nw_g
 
+    is_dlr_mesh = type(wmesh) == MeshDLRImFreq
+    if is_dlr_mesh:
+        iw_values = np.fromiter(wmesh.values(), dtype=complex)
+        is_symmetrized = np.allclose(iw_values, -iw_values[::-1])
+
     # -- Memory Approximation
 
     ng_tr = ntau * np.prod(nk) * norb**2 # storing G(tau, r)
@@ -252,7 +257,10 @@ def imtime_bubble_chi0_wk(g_wk, nw=1, save_memory=False, verbose=True):
     else:
         if not save_memory:
             if verbose: mpi.report('--> chi0_tr_from_grt_PH (bubble in tau & r)')
-            chi0_tr = chi0_tr_from_grt_PH(g_tr)
+            if is_dlr_mesh:
+                chi0_tr = chi0_tr_from_grt_PH(g_tr, is_symmetrized)
+            else:
+                chi0_tr = chi0_tr_from_grt_PH(g_tr)
             del g_tr
 
             if verbose: mpi.report('--> chi_wr_from_chi_tr')