diff --git a/GUI/Model/Sample/CoreAndShellItem.cpp b/GUI/Model/Sample/CoreAndShellItem.cpp
index 74053181a0ef89432e9b7731e2ffff3bcb090ceb..16b809eb01b69554856ca569bf6b155baffee3fd 100644
--- a/GUI/Model/Sample/CoreAndShellItem.cpp
+++ b/GUI/Model/Sample/CoreAndShellItem.cpp
@@ -13,6 +13,7 @@
 //  ************************************************************************************************
 
 #include "GUI/Model/Sample/CoreAndShellItem.h"
+#include "Base/Util/Assert.h"
 #include "GUI/Model/Sample/MaterialModel.h"
 #include "GUI/Model/Sample/ParticleItem.h"
 #include "GUI/Support/Type/VariantUtil.h"
@@ -131,15 +132,14 @@ void CoreAndShellItem::readFrom(QXmlStreamReader* r)
 
 std::unique_ptr<CoreAndShell> CoreAndShellItem::createCoreAndShell() const
 {
-    std::unique_ptr<Particle> P_core{};
-    std::unique_ptr<Particle> P_shell{};
-    if (m_core)
-        P_core = m_core->createParticle();
-    if (m_shell)
-        P_shell = m_shell->createParticle();
-    if (!P_core || !P_shell)
-        throw Error("CoreAndShellItem::createCoreAndShell -> Error. Either "
-                    "core or shell particle is undefined.");
+    ASSERT(m_core);
+    std::unique_ptr<Particle> P_core = m_core->createParticle();
+    ASSERT(P_core);
+
+    ASSERT(m_shell);
+    std::unique_ptr<Particle> P_shell = m_shell->createParticle();
+    ASSERT(P_shell);
+
     auto P_coreshell = std::make_unique<CoreAndShell>(*P_shell, *P_core);
     P_coreshell->setAbundance(abundance());
     if (auto r = createRotation(); r && !r->isIdentity())