diff --git a/Hadrons/Application.cc b/Hadrons/Application.cc
index be2e87a1..e6fb85fa 100644
--- a/Hadrons/Application.cc
+++ b/Hadrons/Application.cc
@@ -48,28 +48,32 @@ Application::Application(void)
 {
     initLogger();
     auto dim = GridDefaultLatt(), mpi = GridDefaultMpi(), loc(dim);
-    locVol_ = 1;
-    for (unsigned int d = 0; d < dim.size(); ++d)
+
+    if (dim.size())
     {
-        loc[d]  /= mpi[d];
-        locVol_ *= loc[d];
+        locVol_ = 1;
+        for (unsigned int d = 0; d < dim.size(); ++d)
+        {
+            loc[d]  /= mpi[d];
+            locVol_ *= loc[d];
+        }
+        LOG(Message) << "====== HADRONS APPLICATION INITIALISATION ======" << std::endl;
+        LOG(Message) << "** Dimensions" << std::endl;
+        LOG(Message) << "Global lattice: " << dim << std::endl;
+        LOG(Message) << "MPI partition : " << mpi << std::endl;
+        LOG(Message) << "Local lattice : " << loc << std::endl;
+        LOG(Message) << std::endl;
+        LOG(Message) << "** Default parameters (and associated C macros)" << std::endl;
+        LOG(Message) << "ASCII output precision  : " << MACOUT(DEFAULT_ASCII_PREC) << std::endl;
+        LOG(Message) << "Fermion implementation  : " << MACOUTS(FIMPLBASE) << std::endl;
+        LOG(Message) << "z-Fermion implementation: " << MACOUTS(ZFIMPLBASE) << std::endl;
+        LOG(Message) << "Scalar implementation   : " << MACOUTS(SIMPLBASE) << std::endl;
+        LOG(Message) << "Gauge implementation    : " << MACOUTS(GIMPLBASE) << std::endl;
+        LOG(Message) << "Eigenvector base size   : " 
+                    << MACOUT(HADRONS_DEFAULT_LANCZOS_NBASIS) << std::endl;
+        LOG(Message) << "Schur decomposition     : " << MACOUTS(HADRONS_DEFAULT_SCHUR) << std::endl;
+        LOG(Message) << std::endl;
     }
-    LOG(Message) << "====== HADRONS APPLICATION INITIALISATION ======" << std::endl;
-    LOG(Message) << "** Dimensions" << std::endl;
-    LOG(Message) << "Global lattice: " << dim << std::endl;
-    LOG(Message) << "MPI partition : " << mpi << std::endl;
-    LOG(Message) << "Local lattice : " << loc << std::endl;
-    LOG(Message) << std::endl;
-    LOG(Message) << "** Default parameters (and associated C macros)" << std::endl;
-    LOG(Message) << "ASCII output precision  : " << MACOUT(DEFAULT_ASCII_PREC) << std::endl;
-    LOG(Message) << "Fermion implementation  : " << MACOUTS(FIMPLBASE) << std::endl;
-    LOG(Message) << "z-Fermion implementation: " << MACOUTS(ZFIMPLBASE) << std::endl;
-    LOG(Message) << "Scalar implementation   : " << MACOUTS(SIMPLBASE) << std::endl;
-    LOG(Message) << "Gauge implementation    : " << MACOUTS(GIMPLBASE) << std::endl;
-    LOG(Message) << "Eigenvector base size   : " 
-                 << MACOUT(HADRONS_DEFAULT_LANCZOS_NBASIS) << std::endl;
-    LOG(Message) << "Schur decomposition     : " << MACOUTS(HADRONS_DEFAULT_SCHUR) << std::endl;
-    LOG(Message) << std::endl;
 }
 
 Application::Application(const Application::GlobalPar &par)
diff --git a/Hadrons/Environment.cc b/Hadrons/Environment.cc
index e7a7ac55..540b3620 100644
--- a/Hadrons/Environment.cc
+++ b/Hadrons/Environment.cc
@@ -43,15 +43,13 @@ HADRONS_ERROR_REF(ObjectDefinition, "no object with address " + std::to_string(a
 // constructor /////////////////////////////////////////////////////////////////
 Environment::Environment(void)
 {
-    dim_         = GridDefaultLatt();
-    nd_          = dim_.size();
-    createGrid<vComplex>(1);
+    dim_ = GridDefaultLatt();
+    nd_  = dim_.size();
     vol_ = 1.;
     for (auto d: dim_)
     {
         vol_ *= d;
     }
-    rng4d_.reset(new GridParallelRNG(getGrid()));
 }
 
 // grids ///////////////////////////////////////////////////////////////////////
@@ -76,8 +74,13 @@ double Environment::getVolume(void) const
 }
 
 // random number generator /////////////////////////////////////////////////////
-GridParallelRNG * Environment::get4dRng(void) const
+GridParallelRNG * Environment::get4dRng(void)
 {
+    if (rng4d_ == nullptr)
+    {
+        rng4d_.reset(new GridParallelRNG(getGrid()));
+    }
+
     return rng4d_.get();
 }
 
diff --git a/Hadrons/Environment.hpp b/Hadrons/Environment.hpp
index b77345c8..05d3d8dd 100644
--- a/Hadrons/Environment.hpp
+++ b/Hadrons/Environment.hpp
@@ -113,7 +113,7 @@ public:
     unsigned int            getNd(void) const;
     double                  getVolume(void) const;
     // random number generator
-    GridParallelRNG *       get4dRng(void) const;
+    GridParallelRNG *       get4dRng(void);
     // general memory management
     void                    addObject(const std::string name,
                                       const int moduleAddress = -1);
diff --git a/Hadrons/Utilities/HadronsXmlValidate.cc b/Hadrons/Utilities/HadronsXmlValidate.cc
new file mode 100644
index 00000000..73cf3139
--- /dev/null
+++ b/Hadrons/Utilities/HadronsXmlValidate.cc
@@ -0,0 +1,64 @@
+/*************************************************************************************
+
+Grid physics library, www.github.com/paboyle/Grid 
+
+Source file: Hadrons/Utilities/HadronsXmlValidate.cc
+
+Copyright (C) 2015-2019
+
+Author: Antonin Portelli <antonin.portelli@me.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+See the full license in the file "LICENSE" in the top level distribution directory
+*************************************************************************************/
+/*  END LEGAL */
+
+#include <Hadrons/Application.hpp>
+
+using namespace Grid;
+using namespace QCD;
+using namespace Hadrons;
+
+int main(int argc, char *argv[])
+{
+    // parse command line
+    std::string parameterFileName;
+    
+    if (argc != 2)
+    {
+        std::cerr << "usage: " << argv[0] << " <parameter file>";
+        std::cerr << std::endl;
+        std::exit(EXIT_FAILURE);
+    }
+    parameterFileName = argv[1];
+    
+    try
+    {
+        Application application(parameterFileName);
+        
+        application.parseParameterFile(parameterFileName);
+        auto &vm = VirtualMachine::getInstance();
+        vm.getModuleGraph();
+        LOG(Message) << "Application valid (check XML warnings though)" 
+                     << std::endl;
+    }
+    catch (const std::exception& e)
+    {
+        Exceptions::abort(e);
+    }
+    
+    return EXIT_SUCCESS;
+}
diff --git a/Hadrons/Utilities/Makefile.am b/Hadrons/Utilities/Makefile.am
index 4f324d6d..6c48d966 100644
--- a/Hadrons/Utilities/Makefile.am
+++ b/Hadrons/Utilities/Makefile.am
@@ -1,8 +1,11 @@
-bin_PROGRAMS = HadronsXmlRun HadronsFermionEP64To32 HadronsContractor HadronsContractorBenchmark
+bin_PROGRAMS = HadronsXmlRun HadronsXmlValidate HadronsFermionEP64To32 HadronsContractor HadronsContractorBenchmark
 
 HadronsXmlRun_SOURCES = HadronsXmlRun.cc
 HadronsXmlRun_LDADD   = ../libHadrons.a ../../Grid/libGrid.a
 
+HadronsXmlValidate_SOURCES = HadronsXmlValidate.cc
+HadronsXmlValidate_LDADD   = ../libHadrons.a ../../Grid/libGrid.a
+
 HadronsFermionEP64To32_SOURCES  = EigenPackCast.cc
 HadronsFermionEP64To32_CXXFLAGS = $(AM_CXXFLAGS) -DFIN=WilsonImplD::FermionField -DFOUT=WilsonImplF::FermionField
 HadronsFermionEP64To32_LDADD    = ../libHadrons.a ../../Grid/libGrid.a