diff --git a/src/classes/PMusrCanvas.cpp b/src/classes/PMusrCanvas.cpp
index a5a3ec2d..9e607797 100644
--- a/src/classes/PMusrCanvas.cpp
+++ b/src/classes/PMusrCanvas.cpp
@@ -718,6 +718,18 @@ void PMusrCanvas::UpdateDataTheoryPad()
         // handle data
         HandleDataSet(i, runNo, data);
         break;
+      case MSR_FITTYPE_BNMR:
+        data = fRunList->GetAsymmetryBNMR(runNo, PRunListCollection::kRunNo);
+        if (!data) { // something wrong
+          fValid = false;
+          // error message
+          cerr << endl << ">> PMusrCanvas::UpdateDataTheoryPad(): **ERROR** couldn't obtain run no " << runNo << " for a beta-NMR asymmetry plot";
+          cerr << endl;
+          return;
+        }
+        // handle data
+        HandleDataSet(i, runNo, data);
+        break;
       case MSR_FITTYPE_ASYM_RRF:
         data = fRunList->GetAsymmetryRRF(runNo, PRunListCollection::kRunNo);
         if (!data) { // something wrong
@@ -742,18 +754,6 @@ void PMusrCanvas::UpdateDataTheoryPad()
         // handle data
         HandleDataSet(i, runNo, data);
         break;
-      case MSR_FITTYPE_BNMR:
-        data = fRunList->GetAsymmetryBNMR(runNo, PRunListCollection::kRunNo);
-        if (!data) { // something wrong
-          fValid = false;
-          // error message
-          cerr << endl << ">> PMusrCanvas::UpdateDataTheoryPad(): **ERROR** couldn't obtain run no " << runNo << " for a beta-NMR asymmetry plot";
-          cerr << endl;
-          return;
-        }
-        // handle data
-        HandleDataSet(i, runNo, data);
-        break;
       case MSR_FITTYPE_NON_MUSR:
         data = fRunList->GetNonMusr(runNo, PRunListCollection::kRunNo);
         if (!data) { // something wrong
diff --git a/src/classes/PRunAsymmetryBNMR.cpp b/src/classes/PRunAsymmetryBNMR.cpp
index f9aa4cfe..0de439aa 100644
--- a/src/classes/PRunAsymmetryBNMR.cpp
+++ b/src/classes/PRunAsymmetryBNMR.cpp
@@ -222,19 +222,19 @@ Double_t PRunAsymmetryBNMR::CalcChiSquare(const std::vector<Double_t>& par)
         break;
       case 2: // alpha != 1, beta == 1
         a = par[fRunInfo->GetAlphaParamNo()-1];
-        f = fTheory->Func(time, par, fFuncValues);
-        asymFcnValue = (f*(a+1.0)-(a-1.0))/((a+1.0)-f*(a-1.0));
+        f = fTheory->Func(time, par, fFuncValues)/2;
+        asymFcnValue = (f*(a+1.0)-(a-1.0))/((a+1.0)-f*(a-1.0)) - (-f*(a+1.0)-(a-1.0))/((a+1.0)+f*(a-1.0));
         break;
       case 3: // alpha == 1, beta != 1
         b = par[fRunInfo->GetBetaParamNo()-1];
-        f = fTheory->Func(time, par, fFuncValues);
-        asymFcnValue = f*(b+1.0)/(2.0-f*(b-1.0));
+        f = fTheory->Func(time, par, fFuncValues)/2;
+        asymFcnValue = f*(b+1.0)/(2.0-f*(b-1.0))-f*(b+1.0)/(2.0+f*(b-1.0));
         break;
       case 4: // alpha != 1, beta != 1
         a = par[fRunInfo->GetAlphaParamNo()-1];
         b = par[fRunInfo->GetBetaParamNo()-1];
-        f = fTheory->Func(time, par, fFuncValues);
-        asymFcnValue = (f*(a*b+1.0)-(a-1.0))/((a+1.0)-f*(a*b-1.0));
+        f = fTheory->Func(time, par, fFuncValues)/2;
+        asymFcnValue = (f*(a*b+1.0)-(a-1.0))/((a+1.0)-f*(a*b-1.0))-(-f*(a*b+1.0)-(a-1.0))/((a+1.0)+f*(a*b-1.0));
         break;
       default:
         asymFcnValue = 0.0;
@@ -1276,7 +1276,7 @@ Bool_t PRunAsymmetryBNMR::PrepareViewData(PRawRunData* runData, UInt_t histoNo[2
     efm = forwardmPacked.GetError()->at(i);
     ebm = backwardmPacked.GetError()->at(i);
     // check that there are indeed bins
-    if (fp+bp != 0.0)
+    if (fp+bp != 0.0) 
       asym = (alpha*fp-bp) / (alpha*beta*fp+bp) - (alpha*fm-bm) / (alpha*beta*fm+bm);
     else
       asym = 0.0;
diff --git a/src/classes/PRunListCollection.cpp b/src/classes/PRunListCollection.cpp
index 6733062c..4fc9e032 100644
--- a/src/classes/PRunListCollection.cpp
+++ b/src/classes/PRunListCollection.cpp
@@ -972,7 +972,7 @@ PRunData* PRunListCollection::GetAsymmetry(UInt_t index, EDataSwitch tag)
 // GetAsymmetryBNMR (public)
 //--------------------------------------------------------------------------
 /**
- * <p>Get a processed asymmetry data set.
+ * <p>Get a processed asymmetry from beta-NMR data set.
  *
  * <b>return:</b>
  * - pointer to the run data set (processed data) if data set is found