added hh, ss symmetry test

src/grogupy/grogu.py

@@ -219,6 +219,10 @@ def main(simulation_parameters: dict, magnetic_entities: list, pairs: list) -> N
     # reformat Hamiltonian and Overlap matrix for manipulations
     hh, ss = build_hh_ss(dh)
 
+    # copy arrays for tests
+    if rank == root_node:
+        hh_test, ss_test = hh.copy(), ss.copy()
+
     # symmetrizing Hamiltonian and Overlap matrix to make them hermitian
     for i in range(dh.lattice.sc_off.shape[0]):
         j = dh.lattice.sc_index(-dh.lattice.sc_off[i])
@@ -227,6 +231,19 @@ def main(simulation_parameters: dict, magnetic_entities: list, pairs: list) -> N
         s1, s1d = ss[i], ss[j]
         ss[i], ss[j] = (s1 + s1d.T.conj()) / 2, (s1d + s1.T.conj()) / 2
 
+    # test symmetrization
+    if rank == root_node:
+        diff_hh = abs(hh - hh_test).max()
+        diff_ss = abs(ss - ss_test).max()
+        if diff_hh > 1e-12:
+            warnings.warn(
+                f"Hamiltonian changed after symmetrization. Largest change is {diff_hh}"
+            )
+        if diff_ss > 1e-12:
+            warnings.warn(
+                f"Overlap matrix changed after symmetrization. Largest change is {diff_hh}"
+            )
+
     # identifying TRS and TRB parts of the Hamiltonian
     TAUY: np.array = np.kron(np.eye(NO), TAU_Y)
     hTR: np.array = np.array(