diff --git a/include/materials/Gas.h b/include/classes/Gas.h
similarity index 100%
rename from include/materials/Gas.h
rename to include/classes/Gas.h
diff --git a/include/materials/Material.h b/include/classes/Material.h
similarity index 100%
rename from include/materials/Material.h
rename to include/classes/Material.h
diff --git a/include/materials/Matrix.h b/include/classes/Matrix.h
similarity index 100%
rename from include/materials/Matrix.h
rename to include/classes/Matrix.h
diff --git a/include/computation/Solver.h b/include/classes/Solver.h
similarity index 100%
rename from include/computation/Solver.h
rename to include/classes/Solver.h
diff --git a/include/materials/System.h b/include/classes/System.h
similarity index 100%
rename from include/materials/System.h
rename to include/classes/System.h
diff --git a/include/computation/Constants.h b/include/namespaces/Constants.h
similarity index 97%
rename from include/computation/Constants.h
rename to include/namespaces/Constants.h
index 07506c72..36c32cdf 100644
--- a/include/computation/Constants.h
+++ b/include/namespaces/Constants.h
@@ -14,8 +14,8 @@
 //                                                                                  //
 //////////////////////////////////////////////////////////////////////////////////////
 
-#ifndef CONSTANT_NUMBERS_H
-#define CONSTANT_NUMBERS_H
+#ifndef CONSTANTS_H
+#define CONSTANTS_H
 
 /**
  * @file Constants.h
diff --git a/src/materials/Matrix.C b/src/classes/Matrix.C
similarity index 100%
rename from src/materials/Matrix.C
rename to src/classes/Matrix.C
diff --git a/src/computation/Solver.C b/src/classes/Solver.C
similarity index 100%
rename from src/computation/Solver.C
rename to src/classes/Solver.C
diff --git a/src/materials/System.C b/src/classes/System.C
similarity index 100%
rename from src/materials/System.C
rename to src/classes/System.C
diff --git a/src/operations/SetGas.C b/src/operations/SetGas.C
index 3d06a97c..e5a5e3a4 100644
--- a/src/operations/SetGas.C
+++ b/src/operations/SetGas.C
@@ -26,52 +26,50 @@ void Simulation::setGas()
 
 void xenon(SciantixArray<Gas> &gas)
 {
-    Gas xe;    
-    xe.setName("Xe");
-	xe.setAtomicNumber(54);
-	xe.setMassNumber(135);
-	xe.setVanDerWaalsVolume(8.48e-29);
-	xe.setDecayRate(0.0);
-	xe.setPrecursorFactor(1.00);
-    gas.push(xe);
+    Gas gas_;    
+    gas_.setName("Xe");
+	gas_.setAtomicNumber(54);
+	gas_.setMassNumber(135);
+	gas_.setVanDerWaalsVolume(8.48e-29);
+	gas_.setDecayRate(0.0);
+	gas_.setPrecursorFactor(1.00);
+    gas.push(gas_);
 
-	Gas xe133;	
-	xe133.setName("Xe133");
-	xe133.setAtomicNumber(54);
-	xe133.setMassNumber(133);
-	xe133.setVanDerWaalsVolume(8.48e-29);
-	xe133.setDecayRate(1.53e-6);
-	xe133.setPrecursorFactor(1.25);
-    gas.push(xe133);
+	gas_.setName("Xe133");
+	gas_.setAtomicNumber(54);
+	gas_.setMassNumber(133);
+	gas_.setVanDerWaalsVolume(8.48e-29);
+	gas_.setDecayRate(1.53e-6);
+	gas_.setPrecursorFactor(1.25);
+    gas.push(gas_);
 }
 
 void krypton(SciantixArray<Gas> &gas)
 {
-    Gas kr;
-	kr.setName("Kr");
-	kr.setAtomicNumber(36);
-	kr.setVanDerWaalsVolume(6.61e-29);
-	kr.setDecayRate(0.0);
-	kr.setPrecursorFactor(1.00);
-    gas.push(kr);
+    Gas gas_;
+	gas_.setName("Kr");
+	gas_.setAtomicNumber(36);
+	gas_.setVanDerWaalsVolume(6.61e-29);
+	gas_.setDecayRate(0.0);
+	gas_.setPrecursorFactor(1.00);
+    gas.push(gas_);
 
-	Gas kr85m;
-	kr85m.setName("Kr85m");
-	kr85m.setAtomicNumber(36);
-	kr85m.setMassNumber(85);
-	kr85m.setVanDerWaalsVolume(6.61e-29);
-	kr85m.setDecayRate(4.3e-5);
-	kr85m.setPrecursorFactor(1.31);
-    gas.push(kr85m);
+	gas_.setName("Kr85m");
+	gas_.setAtomicNumber(36);
+	gas_.setMassNumber(85);
+	gas_.setVanDerWaalsVolume(6.61e-29);
+	gas_.setDecayRate(4.3e-5);
+	gas_.setPrecursorFactor(1.31);
+    gas.push(gas_);
 }
 
 void helium(SciantixArray<Gas> &gas)
 {
-    Gas he;
-	he.setName("He");
-	he.setAtomicNumber(2);
-	he.setVanDerWaalsVolume(9.97e-30);
-	he.setDecayRate(0.0);
-	he.setPrecursorFactor(1.00);
-    gas.push(he);
+    Gas gas_;
+	gas_.setName("He");
+	gas_.setAtomicNumber(2);
+	gas_.setVanDerWaalsVolume(9.97e-30);
+	gas_.setDecayRate(0.0);
+	gas_.setPrecursorFactor(1.00);
+    gas.push(gas_);
 }
\ No newline at end of file