diff --git a/acc/mhd_solver/stencil_assembly.sas b/acc/mhd_solver/stencil_assembly.sas
index f9025f9..e095d08 100644
--- a/acc/mhd_solver/stencil_assembly.sas
+++ b/acc/mhd_solver/stencil_assembly.sas
@@ -13,6 +13,50 @@ gradient(in Scalar vertex)
                     derz(vertexIdx, vertex)};
 }
 
+Preprocessed Scalar
+der6x_upwd(in Scalar vertex), 
+{
+    return (Scalar){(1.0/60.0)*inv_ds* (
+                    - 20.0* vertex[vertexIdx.x,   vertexIdx.y, vertexIdx.z] 
+                    + 15.0*(vertex[vertexIdx.x, vertexIdx.y+1, vertexIdx.z] + vertex[vertexIdx.x, vertexIdx.y-1, vertexIdx.z]) 
+                    -  6.0*(vertex[vertexIdx.x, vertexIdx.y+2, vertexIdx.z] + vertex[vertexIdx.x, vertexIdx.y-2, vertexIdx.z])
+                    +       vertex[vertexIdx.x, vertexIdx.y+3, vertexIdx.z] + vertex[vertexIdx.x, vertexIdx.y-3, vertexIdx.z];
+                    )}
+}
+
+Preprocessed Scalar
+der6x_upwd(in Scalar vertex), 
+{
+    return (Scalar){(1.0/60.0)*inv_ds* (
+                    - 20.0* vertex[vertexIdx.x,   vertexIdx.y, vertexIdx.z] 
+                    + 15.0*(vertex[vertexIdx.x, vertexIdx.y+1, vertexIdx.z] + vertex[vertexIdx.x, vertexIdx.y-1, vertexIdx.z]) 
+                    -  6.0*(vertex[vertexIdx.x, vertexIdx.y+2, vertexIdx.z] + vertex[vertexIdx.x, vertexIdx.y-2, vertexIdx.z])
+                    +       vertex[vertexIdx.x, vertexIdx.y+3, vertexIdx.z] + vertex[vertexIdx.x, vertexIdx.y-3, vertexIdx.z];
+                    )}
+}
+
+Preprocessed Scalar
+der6x_upwd(in Scalar vertex), 
+{
+    return (Scalar){(1.0/60.0)*inv_ds* (
+                    - 20.0* vertex[vertexIdx.x,   vertexIdx.y, vertexIdx.z] 
+                    + 15.0*(vertex[vertexIdx.x, vertexIdx.y, vertexIdx.z+1] + vertex[vertexIdx.x, vertexIdx.y, vertexIdx.z-1]) 
+                    -  6.0*(vertex[vertexIdx.x, vertexIdx.y, vertexIdx.z+2] + vertex[vertexIdx.x, vertexIdx.y, vertexIdx.z-2])
+                    +       vertex[vertexIdx.x, vertexIdx.y, vertexIdx.z+3] + vertex[vertexIdx.x, vertexIdx.y, vertexIdx.z-3];
+                    )}
+}
+
+Preprocessed Scalar
+der6_upwd(in Scalar vertex)
+{
+    der6 =  
+         
+         
+         
+
+    return der6;
+}
+
 Preprocessed Matrix
 hessian(in Scalar vertex)
 {