diff --git a/src/main.cpp b/src/main.cpp
index 41f9cfc825..b9886c6c0d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -12,11 +12,12 @@
 ------------------------------------------------------------------------- */
 
 #include "lammps.h"
+
 #include "input.h"
 #include "mdi_interface.h"
 
-#include <mpi.h>
 #include <cstdlib>
+#include <mpi.h>
 
 #if defined(LAMMPS_TRAP_FPE) && defined(_GNU_SOURCE)
 #include <fenv.h>
@@ -34,26 +35,24 @@ using namespace LAMMPS_NS;
 
 int main(int argc, char **argv)
 {
-  MPI_Init(&argc,&argv);
+  MPI_Init(&argc, &argv);
 
-  // initialize MDI
-  if ( MDI_Init(&argc,&argv) )
-    MPI_Abort(MPI_COMM_WORLD, 1);
+  // initialize MDI or MDI dummy interface
+
+  int mdi_flag;
+  if (MDI_Init(&argc, &argv)) MPI_Abort(MPI_COMM_WORLD, 1);
+  if (MDI_Initialized(&mdi_flag)) MPI_Abort(MPI_COMM_WORLD, 1);
 
   // get the MPI communicator that spans all ranks running LAMMPS
   // when using MDI, this may be a subset of MPI_COMM_WORLD
-  MPI_Comm lammps_comm = MPI_COMM_WORLD;
-  int mdi_flag;
-  if ( MDI_Initialized(&mdi_flag) )
-    MPI_Abort(MPI_COMM_WORLD, 1);
-  if ( mdi_flag ) {
-    if ( MDI_MPI_get_world_comm( &lammps_comm ) )
-      MPI_Abort(MPI_COMM_WORLD, 1);
-  }
 
-// enable trapping selected floating point exceptions.
-// this uses GNU extensions and is only tested on Linux
-// therefore we make it depend on -D_GNU_SOURCE, too.
+  MPI_Comm lammps_comm = MPI_COMM_WORLD;
+  if (mdi_flag)
+    if (MDI_MPI_get_world_comm(&lammps_comm)) MPI_Abort(MPI_COMM_WORLD, 1);
+
+  // enable trapping selected floating point exceptions.
+  // this uses GNU extensions and is only tested on Linux
+  // therefore we make it depend on -D_GNU_SOURCE, too.
 
 #if defined(LAMMPS_TRAP_FPE) && defined(_GNU_SOURCE)
   fesetenv(FE_NOMASK_ENV);
@@ -65,27 +64,27 @@ int main(int argc, char **argv)
 
 #ifdef LAMMPS_EXCEPTIONS
   try {
-    LAMMPS *lammps = new LAMMPS(argc,argv,lammps_comm);
+    LAMMPS *lammps = new LAMMPS(argc, argv, lammps_comm);
     lammps->input->file();
     delete lammps;
-  } catch(LAMMPSAbortException &ae) {
+  } catch (LAMMPSAbortException &ae) {
     MPI_Abort(ae.universe, 1);
-  } catch(LAMMPSException &e) {
+  } catch (LAMMPSException &e) {
     MPI_Barrier(lammps_comm);
     MPI_Finalize();
     exit(1);
-  } catch(fmt::format_error &fe) {
-    fprintf(stderr,"fmt::format_error: %s\n", fe.what());
+  } catch (fmt::format_error &fe) {
+    fprintf(stderr, "fmt::format_error: %s\n", fe.what());
     MPI_Abort(MPI_COMM_WORLD, 1);
     exit(1);
   }
 #else
   try {
-    LAMMPS *lammps = new LAMMPS(argc,argv,lammps_comm);
+    LAMMPS *lammps = new LAMMPS(argc, argv, lammps_comm);
     lammps->input->file();
     delete lammps;
-  } catch(fmt::format_error &fe) {
-    fprintf(stderr,"fmt::format_error: %s\n", fe.what());
+  } catch (fmt::format_error &fe) {
+    fprintf(stderr, "fmt::format_error: %s\n", fe.what());
     MPI_Abort(MPI_COMM_WORLD, 1);
     exit(1);
   }