fix IrregularLattice with infinte MPS bc.

tenpy · Jun 9, 2020 · 037ad76 · 037ad76
1 parent 7cb4545
commit 037ad76
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Showing 2 changed files with 14 additions and 7 deletions.
diff --git a/tenpy/models/lattice.py b/tenpy/models/lattice.py
@@ -857,7 +857,6 @@ def possible_couplings(self, u1, u2, dx):
         if any([s == 0 for s in coupling_shape]):
             return [], [], np.zeros([0, self.dim]), coupling_shape
         Ls = np.array(self.Ls)
-        N_sites_per_ring = self.N_sites_per_ring
         mps_i, lat_i = self.mps_lat_idx_fix_u(u1)
         lat_j_shifted = lat_i + dx
         lat_j = np.mod(lat_j_shifted, Ls)  # assuming PBC
@@ -874,7 +873,8 @@ def possible_couplings(self, u1, u2, dx):
         mps_j = self.lat2mps_idx(np.concatenate([lat_j, [[u2]] * len(lat_j)], axis=1))
         if self.bc_MPS == 'infinite':
             # shift j by whole MPS unit cells for couplings along the infinite direction
-            mps_j_shift = (lat_j_shifted[:, 0] - lat_j[:, 0]) * N_sites_per_ring
+            # N_sites_per_ring might not be set for IrregularLattice
+            mps_j_shift = (lat_j_shifted[:, 0] - lat_j[:, 0]) * self.N_sites // self.N_rings
             mps_j += mps_j_shift
             # finally, ensure 0 <= min(i, j) < N_sites.
             mps_ij_shift = np.where(mps_j_shift < 0, -mps_j_shift, 0)
@@ -967,7 +967,9 @@ def possible_multi_couplings(self, ops):
         u = np.broadcast_to(u, lat_ijkl.shape[:2] + (1, ))
         mps_ijkl = self.lat2mps_idx(np.concatenate([lat_ijkl, u], axis=2))
         if self.bc_MPS == 'infinite':
-            mps_ijkl += (lat_ijkl_shifted[keep, :, 0] - lat_ijkl[:, :, 0]) * self.N_sites_per_ring
+            # N_sites_per_ring might not be set for IrregularLattice
+            mps_ijkl += ((lat_ijkl_shifted[keep, :, 0] - lat_ijkl[:, :, 0]) * self.N_sites //
+                         self.N_rings)
         return mps_ijkl, lat_indices, coupling_shape
 
     def _keep_possible_multi_couplings(self, lat_ijkl, lat_ijkl_shifted, u_ijkl):
@@ -1433,7 +1435,7 @@ def _keep_possible_multi_couplings(self, lat_ijkl, lat_ijkl_shifted, u_ijkl):
     def _set_Ls(self, Ls):
         super()._set_Ls(Ls)
         # N_sites, N_sites_per_ring set by order setter
-        self.N_sites = None
+        # self.N_sites = None
         self.N_sites_per_ring = None
 
 

diff --git a/tests/test_lattice.py b/tests/test_lattice.py
@@ -104,8 +104,9 @@ def test_IrregularLattice():
 
         ops = [(None, dx, u1), (None, [0, 0], u0)]
         m_ji, m_lat_indices, m_coupling_shape = ir.possible_multi_couplings(ops)
-        # npt.assert_equal(m_ji[1, :], np.array(expect['i']))
-        # npt.assert_equal(m_ji[0, :], np.array(expect['j']))
+        sort = np.lexsort(m_lat_indices.T)
+        npt.assert_equal(m_ji[sort, 1], np.array(expect['i']))
+        npt.assert_equal(m_ji[sort, 0], np.array(expect['j']))
 
 
 def test_number_nn():
@@ -175,7 +176,11 @@ def test_lattice_order():
 
 
 def test_possible_couplings():
-    lat_reg = lattice.Honeycomb(2, 3, [None, None], order="snake", bc="periodic")
+    lat_reg = lattice.Honeycomb(2,
+                                3, [None, None],
+                                order="snake",
+                                bc="periodic",
+                                bc_MPS="infinite")
     lat_irreg = lattice.IrregularLattice(lat_reg, remove=[[0, 0, 0]])
     u0, u1 = 0, 1
     for lat in [lat_reg, lat_irreg]: