Updated citools.interfaces to add the excitation parity phase

Author: alexvakimov

src/libra_py/citools/interfaces.py

@@ -915,6 +915,20 @@ def sd_and_csf_overlaps_singlet(
 
     dets = list(mapped_basis)
 
+
+    # ==================================================================
+    # Excitations parity phases
+    # ==================================================================
+
+    nbas = len(mapped_basis)
+
+    Phases = [1.0] # ground state reference
+    for i in range(1, nbas):
+        phase, new_det = sd.excitation_phase_from_mapping(mapped_basis[0], mapped_basis[i])
+        Phases.append(phase)
+        #print(phase)
+
+
     # ==================================================================
     # Overlap matrices
     # ==================================================================
@@ -927,7 +941,8 @@ def sd_and_csf_overlaps_singlet(
 
 
     st_sd = sd.slater_overlap_matrix(
-        dets, dets, st_mo_dense, complex_valued=False
+        dets, dets, st_mo_dense, complex_valued=False, 
+        phases_A=Phases, phases_B=Phases
     )
 
     if st_sd.shape[0] != st_sd.shape[1]: