Merge pull request #355 from emstoudenmire/fix_total_qn

Fix totalQN function to always succeed if lims set
ITensor · May 8, 2020 · 0beccc5 · 0beccc5
2 parents 26f0783 + b95625f
commit 0beccc5
Showing 1 changed file with 8 additions and 4 deletions.
diff --git a/itensor/mps/mpsalgs.cc b/itensor/mps/mpsalgs.cc
@@ -241,10 +241,14 @@ checkQNs(MPS const& psi)
 QN
 totalQN(MPS const& psi)
     {
-    const int center = findCenter(psi);
-    if(center == -1)
-        Error("Could not find ortho. center");
-    return div(psi(center));
+    auto tq = QN();
+    auto sj = psi.leftLim()+1;
+    auto ej = psi.rightLim()-1;
+    for(int j = sj; j <= ej; ++j)
+        {
+        tq += flux(psi(j));
+        }
+    return tq;
     }
 
 } //namespace itensor