From 57e0e64ffe73029fc660c3def9711cfa7ad9a936 Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Fri, 9 Oct 2020 12:47:13 -0400
Subject: [PATCH] No MPI communicaton after MPI_Finalize() and no
 MPI_Finalize() unless we are initialized.

---
 src/library.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/library.cpp b/src/library.cpp
index ad6ba34804..db05faf9fb 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -337,8 +337,15 @@ more MPI calls may be made.
 
 void lammps_mpi_finalize()
 {
-  MPI_Barrier(MPI_COMM_WORLD);
-  MPI_Finalize();
+  int flag;
+  MPI_Initialized(&flag);
+  if (flag) {
+    MPI_Finalized(&flag);
+    if (!flag) {
+      MPI_Barrier(MPI_COMM_WORLD);
+      MPI_Finalize();
+    }
+  }
 }
 
 /* ---------------------------------------------------------------------- */