void CreateGeo()
{
  //-----User Settings:-----------------------------------------------
  TString  OutputFile     = "geo.root";
  TString  ParOutputfile  = "geoparams.root";
  TString  MediaFile      = "media_pnd.geo";
  gDebug                  = 0;
  TString digiFile        = "all.par"; //The emc run the hit producer directly 
  Bool_t UseBoxGenerator  = kTRUE;

  Double_t BeamMomentum = 15.; // beam momentum ONLY for the scaling of the dipole field.

  //------------------------------------------------------------------
  TStopwatch timer;
  timer.Start();
  gRandom->SetSeed(); 

  // Create the Simulation run manager--------------------------------
  FairRunSim *fRun = new FairRunSim();
  fRun->SetName("TGeant3");
  fRun->SetOutputFile(OutputFile.Data());
  fRun->SetWriteRunInfoFile(kFALSE);
  fRun->SetBeamMom(BeamMomentum);
  fRun->SetMaterials(MediaFile.Data());
  FairRuntimeDb *rtdb=fRun->GetRuntimeDb();
  
  // Set the parameters 
  //-------------------------------
  TString allDigiFile = gSystem->Getenv("VMCWORKDIR");
  allDigiFile += "/macro/params/";
  allDigiFile += digiFile;
  
  //---------------------Set Parameter output      ---------- 
  Bool_t kParameterMerged=kTRUE;
  FairParRootFileIo* output=new FairParRootFileIo(kParameterMerged);
  output->open(ParOutputfile.Data());
  rtdb->setOutput(output);

  // Create and add detectors

  //-------------------------  CAVE      -----------------
  FairModule *Cave= new PndCave("CAVE");
  Cave->SetGeometryFileName("pndcave.geo");
  fRun->AddModule(Cave); 
  //-------------------------  STT       -----------------
  FairDetector *SttExp = new PndStt("STT", kTRUE);
  SttExp->SetGeometryFileName("straw_prototype_beam.geo");
  fRun->AddModule(SttExp);

  // Create and Set Event Generator
  //-------------------------------
  FairPrimaryGenerator* primGen = new FairPrimaryGenerator();
  fRun->SetGenerator(primGen);
	 
  // Box Generator
  FairBoxGenerator* boxGen = new FairBoxGenerator(2212, 1); // 13 = muon; 1 = multipl.
  boxGen->SetPRange(1.); // GeV/c
  boxGen->SetPhiRange(0., 360.); // Azimuth angle range [degree]
  boxGen->SetThetaRange(-4.57,4.57); // Polar angle in lab system range [degree] 4.57
  boxGen->SetBoxXYZ(-1.5, -1.5, 1.5, 1.5, 0);
  primGen->AddGenerator(boxGen);

  fRun->SetStoreTraj(kTRUE);
  //-------------------------  Initialize the RUN  -----------------  
  fRun->Init();
  //-------------------------  Run the Simulation  -----------------   
  fRun->Run(0);
  //-------------------------  Save the parameters ----------------- 
  rtdb->saveOutput();
  rtdb->print();
  //------------------------Print some info and exit----------------     
  timer.Stop();
  Double_t rtime = timer.RealTime();
  Double_t ctime = timer.CpuTime();
  printf("RealTime=%f seconds, CpuTime=%f seconds\n",rtime,ctime);
 
}