From c9cf8b57f4ce3ade34f55911824b5a126bf3200a Mon Sep 17 00:00:00 2001
From: "Ryan S. Elliott" <relliott@umn.edu>
Date: Wed, 3 Feb 2021 10:00:25 -0600
Subject: [PATCH 1/4] Fix behavor of a 2nd call to 'pair_style kim ...' & a bug
 for parameter changes

---
 src/KIM/pair_kim.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/KIM/pair_kim.cpp b/src/KIM/pair_kim.cpp
index ee6f5f98a5..ecb62cdf7a 100644
--- a/src/KIM/pair_kim.cpp
+++ b/src/KIM/pair_kim.cpp
@@ -540,6 +540,19 @@ void PairKIM::coeff(int narg, char **arg)
     kimerror = KIM_Model_ClearThenRefresh(pkim);
     if (kimerror)
       error->all(FLERR,"KIM KIM_Model_ClearThenRefresh returned error");
+
+    // Update cached quantities that may have changed due to Refresh
+    KIM_Model_GetInfluenceDistance(pkim, &kim_global_influence_distance);
+    KIM_Model_GetNeighborListPointers(
+        pkim,
+        &kim_number_of_neighbor_lists,
+        &kim_cutoff_values,
+        &modelWillNotRequestNeighborsOfNoncontributingParticles);
+    if (neighborLists) {
+      delete [] neighborLists;
+      neighborLists = 0;
+    }
+    neighborLists = new NeighList*[kim_number_of_neighbor_lists];
   }
 }
 
@@ -809,6 +822,8 @@ void PairKIM::kim_free()
       error->all(FLERR,"Unable to destroy Compute Arguments Object");
 
     KIM_Model_Destroy(&pkim);
+
+    lmps_maxalloc = 0;
   }
   kim_init_ok = false;
 }

From 8da3bc91444523948433f01e2a90701bfcfa81a0 Mon Sep 17 00:00:00 2001
From: "Ryan S. Elliott" <relliott@umn.edu>
Date: Thu, 4 Feb 2021 09:47:29 -0600
Subject: [PATCH 2/4] Increment instance_me in pair_kim to ensure neighbor
 correct list updates

---
 src/KIM/pair_kim.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/KIM/pair_kim.cpp b/src/KIM/pair_kim.cpp
index ecb62cdf7a..53ccdc1d73 100644
--- a/src/KIM/pair_kim.cpp
+++ b/src/KIM/pair_kim.cpp
@@ -550,7 +550,7 @@ void PairKIM::coeff(int narg, char **arg)
         &modelWillNotRequestNeighborsOfNoncontributingParticles);
     if (neighborLists) {
       delete [] neighborLists;
-      neighborLists = 0;
+      neighborLists = nullptr;
     }
     neighborLists = new NeighList*[kim_number_of_neighbor_lists];
   }
@@ -604,6 +604,9 @@ void PairKIM::init_style()
     neighbor->requests[irequest]->cutoff
       = kim_cutoff_values[i] + neighbor->skin;
   }
+  // increment instance_me in case of need to change the neighbor list
+  // request settings
+  instance_me += 1;
 }
 
 /* ----------------------------------------------------------------------
@@ -823,7 +826,7 @@ void PairKIM::kim_free()
 
     KIM_Model_Destroy(&pkim);
 
-    lmps_maxalloc = 0;
+    lmps_maxalloc = 0;  // reinitialize member variable
   }
   kim_init_ok = false;
 }
@@ -874,7 +877,7 @@ void PairKIM::kim_init()
     &modelWillNotRequestNeighborsOfNoncontributingParticles);
   if (neighborLists) {
     delete [] neighborLists;
-    neighborLists = 0;
+    neighborLists = nulptr;
   }
   neighborLists = new NeighList*[kim_number_of_neighbor_lists];
 

From 302be3f946c470ccbf9a156f9ae5f00c224899d4 Mon Sep 17 00:00:00 2001
From: "Ryan S. Elliott" <relliott@umn.edu>
Date: Thu, 4 Feb 2021 10:09:14 -0600
Subject: [PATCH 3/4] Fix typo

---
 src/KIM/pair_kim.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/KIM/pair_kim.cpp b/src/KIM/pair_kim.cpp
index 53ccdc1d73..2f1fb9da3e 100644
--- a/src/KIM/pair_kim.cpp
+++ b/src/KIM/pair_kim.cpp
@@ -877,7 +877,7 @@ void PairKIM::kim_init()
     &modelWillNotRequestNeighborsOfNoncontributingParticles);
   if (neighborLists) {
     delete [] neighborLists;
-    neighborLists = nulptr;
+    neighborLists = nullptr;
   }
   neighborLists = new NeighList*[kim_number_of_neighbor_lists];
 

From 5256631bee97c06e7c302e4b722111e0e3303b11 Mon Sep 17 00:00:00 2001
From: Yaser Afshar <ya.afshar@gmail.com>
Date: Thu, 4 Feb 2021 11:08:39 -0600
Subject: [PATCH 4/4] test for correctly supporting the use of multiple calls
 to pair_style kim

---
 unittest/commands/test_kim_commands.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/unittest/commands/test_kim_commands.cpp b/unittest/commands/test_kim_commands.cpp
index 4e16e28783..275a9eae3a 100644
--- a/unittest/commands/test_kim_commands.cpp
+++ b/unittest/commands/test_kim_commands.cpp
@@ -219,6 +219,20 @@ TEST_F(KimCommandsTest, kim_interactions)
 
     int ifix = lmp->modify->find_fix("KIM_MODEL_STORE");
     ASSERT_GE(ifix, 0);
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("clear");
+    lmp->input->one("kim_init LennardJones_Ar real");
+    lmp->input->one("lattice fcc 4.4300");
+    lmp->input->one("region box block 0 10 0 10 0 10");
+    lmp->input->one("create_box 1 box");
+    lmp->input->one("create_atoms 1 box");
+    lmp->input->one("kim_interactions Ar");
+    lmp->input->one("mass 1 39.95");
+    lmp->input->one("run 1");
+    lmp->input->one("kim_interactions Ar");
+    lmp->input->one("run 1");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
 }
 
 TEST_F(KimCommandsTest, kim_param)