diff --git a/NPLib/Physics/NPNucleus.cxx b/NPLib/Physics/NPNucleus.cxx
index 44038da618164558bd4df79f4ba6b84fbde418c5..b8e740f86e0e396dcffab160b40e7f10bf2c554c 100644
--- a/NPLib/Physics/NPNucleus.cxx
+++ b/NPLib/Physics/NPNucleus.cxx
@@ -71,10 +71,16 @@ void Nucleus::SetUp(string isotope){
 
   // Replace the p,d,t,a by there standard name:
   if(isotope=="p") isotope="1H";
+	else if(isotope=="n") isotope="1n";
   else if(isotope=="d") isotope="2H";
   else if(isotope=="t") isotope="3H";
   else if(isotope=="a") isotope="4He";
-
+	else if(isotope=="4n"){ // tetraneutron @Eres = 0
+		string line = "004 0000   4n      32285.268   0.0005                       219.4    ys 0.6    1/2+          00 02PaDGt   B-=100";
+		Extract(line.data());
+		return;
+	}
+	
   ifstream inFile;
   string Path = getenv("NPTOOL") ;
   string FileName = Path + "/NPLib/Physics/nubtab03.asc";
@@ -105,6 +111,10 @@ Nucleus::Nucleus(int Z, int A)
 {
   //----------- Constructor Using nubtab03.asc by Z and A----------
 
+	if(Z==0 && A==4){
+		SetUp("4n");
+		return;
+	}
   // open the file to read and check if it is open
   ifstream inFile;
   string Path = getenv("NPTOOL") ;
diff --git a/NPSimulation/Core/MaterialManager.cc b/NPSimulation/Core/MaterialManager.cc
index 29bdcad13612925cf79e1a5af4412854b96b4ed7..06c59632b53d8df98d3771372bdb1547f6dac286 100644
--- a/NPSimulation/Core/MaterialManager.cc
+++ b/NPSimulation/Core/MaterialManager.cc
@@ -295,7 +295,30 @@ G4Material* MaterialManager::GetMaterialFromLibrary(string Name,double density){
             m_Material[Name]=material;
             return material;
         }
-         
+				else  if(Name == "He_gas"){
+            if(!density)
+							density = 0.0001665*g/cm3; // room temp, 1 atm
+            G4Material* material = new G4Material("NPS_"+Name, density,1);
+            material->AddElement(GetElementFromLibrary("He"),1);
+            m_Material[Name]=material;
+            return material;
+				}
+				else  if(Name == "O2_gas"){
+            if(!density)
+							density = 0.001331*g/cm3; // room temp, 1 atm
+            G4Material* material = new G4Material("NPS_"+Name, density,1);
+            material->AddElement(GetElementFromLibrary("O"),2);
+            m_Material[Name]=material;
+            return material;
+				}
+				else  if(Name == "Ti"){
+            if(!density)
+							density = 4.5189*g/cm3;
+            G4Material* material = new G4Material("NPS_"+Name, density,1);
+            material->AddElement(GetElementFromLibrary("Ti"),1);
+            m_Material[Name]=material;
+            return material;
+				}      
         // Usual detector material
         else  if(Name == "Si"){
             if(!density)