diff --git a/testApp/chemFoam.C b/testApp/chemFoam.C
index ffaf40f..6c3d8b2 100644
--- a/testApp/chemFoam.C
+++ b/testApp/chemFoam.C
@@ -122,11 +122,40 @@ int main(int argc, char *argv[])
         diff.correct();
 
         // Cantera gas transport
-        gas_.setState_TPY(T[i], p0, XY.data());
-
+        gas_.setState_TPY(T[i], p[0], XY.data());
 
         scalarField Dc (composition.species().size(), 0.0);
-        tr_->getMixDiffCoeffsMass(Dc.data());
+        scalarField Dij (composition.species().size()*composition.species().size(), 0.0);
+
+        const scalar relTol = 1.0e-15;
+
+        // check for singular case (Xi = 1)
+        label idxFracOne = -1;
+        scalar sumX = sum(XY);
+        forAll (XY, i)
+        {
+            if ((sumX-XY[i])/sumX < relTol)
+            {
+                idxFracOne = i;
+                break;
+            }
+        }
+
+        if (idxFracOne < 0)
+        {
+            tr_->getMixDiffCoeffsMass(Dc.data());
+        }
+        else
+        {
+            label nSp = nCanteraSp_;
+            tr_->getBinaryDiffCoeffs(nSp, Dij.data());
+
+            forAll(Dc, i)
+            {
+                Dc[i] = Dij[nSp*idxFracOne+i] / p[0];
+            }
+        }
+
 
         forAll(thermo.composition().species(), k)
         {