diff --git a/src/ORIENT/fix_orient_bcc.cpp b/src/ORIENT/fix_orient_bcc.cpp
index fd5ce748d6..8a380e01a7 100644
--- a/src/ORIENT/fix_orient_bcc.cpp
+++ b/src/ORIENT/fix_orient_bcc.cpp
@@ -91,7 +91,6 @@ FixOrientBCC::FixOrientBCC(LAMMPS *lmp, int narg, char **arg) :
 
   // initializations
 
-  half_bcc_nn = 4;
   use_xismooth = false;
   double xicutoff = 1.57;
   xicutoffsq = xicutoff * xicutoff;
@@ -107,7 +106,7 @@ FixOrientBCC::FixOrientBCC(LAMMPS *lmp, int narg, char **arg) :
 
     FILE *inpfile = fopen(xifilename,"r");
     if (inpfile == nullptr) error->one(FLERR,"Fix orient/bcc file open failed");
-    for (int i = 0; i < 4; i++) {
+    for (int i = 0; i < half_bcc_nn; i++) {
       result = fgets(line,IMGMAX,inpfile);
       if (!result) error->one(FLERR,"Fix orient/bcc file read failed");
       count = sscanf(line,"%lg %lg %lg",&Rxi[i][0],&Rxi[i][1],&Rxi[i][2]);
@@ -117,7 +116,7 @@ FixOrientBCC::FixOrientBCC(LAMMPS *lmp, int narg, char **arg) :
 
     inpfile = fopen(chifilename,"r");
     if (inpfile == nullptr) error->one(FLERR,"Fix orient/bcc file open failed");
-    for (int i = 0; i < 4; i++) {
+    for (int i = 0; i < half_bcc_nn; i++) {
       result = fgets(line,IMGMAX,inpfile);
       if (!result) error->one(FLERR,"Fix orient/bcc file read failed");
       count = sscanf(line,"%lg %lg %lg",&Rchi[i][0],&Rchi[i][1],&Rchi[i][2]);
@@ -126,12 +125,12 @@ FixOrientBCC::FixOrientBCC(LAMMPS *lmp, int narg, char **arg) :
     fclose(inpfile);
   }
 
-  MPI_Bcast(&Rxi[0][0],18,MPI_DOUBLE,0,world);
-  MPI_Bcast(&Rchi[0][0],18,MPI_DOUBLE,0,world);
+  MPI_Bcast(&Rxi[0][0],half_bcc_nn*3,MPI_DOUBLE,0,world);
+  MPI_Bcast(&Rchi[0][0],half_bcc_nn*3,MPI_DOUBLE,0,world);
 
   // make copy of the reference vectors
 
-  for (int i = 0; i < 4; i++)
+  for (int i = 0; i < half_bcc_nn; i++)
     for (int j = 0; j < 3; j++) {
       half_xi_chi_vec[0][i][j] = Rxi[i][j];
       half_xi_chi_vec[1][i][j] = Rchi[i][j];
@@ -144,7 +143,7 @@ FixOrientBCC::FixOrientBCC(LAMMPS *lmp, int narg, char **arg) :
   double xi_sq,dxi[3],rchi[3];
 
   xiid = 0.0;
-  for (int i = 0; i < 4; i++) {
+  for (int i = 0; i < half_bcc_nn; i++) {
     rchi[0] = Rchi[i][0];
     rchi[1] = Rchi[i][1];
     rchi[2] = Rchi[i][2];
diff --git a/src/ORIENT/fix_orient_bcc.h b/src/ORIENT/fix_orient_bcc.h
index 858b9bb1b4..82d9829397 100644
--- a/src/ORIENT/fix_orient_bcc.h
+++ b/src/ORIENT/fix_orient_bcc.h
@@ -69,9 +69,9 @@ class FixOrientBCC : public Fix {
   char *xifilename, *chifilename;    // file names for 2 crystal orientations
 
   bool use_xismooth;
-  double Rxi[8][3] = {0}, Rchi[8][3] = {0}, half_xi_chi_vec[2][4][3] = {0};
+  static constexpr int half_bcc_nn = 4;
+  double Rxi[half_bcc_nn][3] = {}, Rchi[half_bcc_nn][3] = {}, half_xi_chi_vec[2][half_bcc_nn][3] = {};
   double xiid, xi0, xi1, xicutoffsq, cutsq, added_energy;
-  int half_bcc_nn;
 
   int nmax;          // expose 2 per-atom quantities
   double **order;    // order param and normalized order param
diff --git a/src/ORIENT/fix_orient_fcc.cpp b/src/ORIENT/fix_orient_fcc.cpp
index c5fe269e5b..30321f9145 100644
--- a/src/ORIENT/fix_orient_fcc.cpp
+++ b/src/ORIENT/fix_orient_fcc.cpp
@@ -89,7 +89,6 @@ FixOrientFCC::FixOrientFCC(LAMMPS *lmp, int narg, char **arg) :
 
   // initializations
 
-  half_fcc_nn = 6;
   use_xismooth = false;
   double xicutoff = 1.57;
   xicutoffsq = xicutoff * xicutoff;
@@ -105,7 +104,7 @@ FixOrientFCC::FixOrientFCC(LAMMPS *lmp, int narg, char **arg) :
 
     FILE *inpfile = fopen(xifilename,"r");
     if (inpfile == nullptr) error->one(FLERR,"Fix orient/fcc file open failed");
-    for (int i = 0; i < 6; i++) {
+    for (int i = 0; i < half_fcc_nn; i++) {
       result = fgets(line,IMGMAX,inpfile);
       if (!result) error->one(FLERR,"Fix orient/fcc file read failed");
       count = sscanf(line,"%lg %lg %lg",&Rxi[i][0],&Rxi[i][1],&Rxi[i][2]);
@@ -115,7 +114,7 @@ FixOrientFCC::FixOrientFCC(LAMMPS *lmp, int narg, char **arg) :
 
     inpfile = fopen(chifilename,"r");
     if (inpfile == nullptr) error->one(FLERR,"Fix orient/fcc file open failed");
-    for (int i = 0; i < 6; i++) {
+    for (int i = 0; i < half_fcc_nn; i++) {
       result = fgets(line,IMGMAX,inpfile);
       if (!result) error->one(FLERR,"Fix orient/fcc file read failed");
       count = sscanf(line,"%lg %lg %lg",&Rchi[i][0],&Rchi[i][1],&Rchi[i][2]);
@@ -124,12 +123,12 @@ FixOrientFCC::FixOrientFCC(LAMMPS *lmp, int narg, char **arg) :
     fclose(inpfile);
   }
 
-  MPI_Bcast(&Rxi[0][0],18,MPI_DOUBLE,0,world);
-  MPI_Bcast(&Rchi[0][0],18,MPI_DOUBLE,0,world);
+  MPI_Bcast(&Rxi[0][0],half_fcc_nn*3,MPI_DOUBLE,0,world);
+  MPI_Bcast(&Rchi[0][0],half_fcc_nn*3,MPI_DOUBLE,0,world);
 
   // make copy of the reference vectors
 
-  for (int i = 0; i < 6; i++)
+  for (int i = 0; i < half_fcc_nn; i++)
     for (int j = 0; j < 3; j++) {
       half_xi_chi_vec[0][i][j] = Rxi[i][j];
       half_xi_chi_vec[1][i][j] = Rchi[i][j];
@@ -142,7 +141,7 @@ FixOrientFCC::FixOrientFCC(LAMMPS *lmp, int narg, char **arg) :
   double xi_sq,dxi[3],rchi[3];
 
   xiid = 0.0;
-  for (int i = 0; i < 6; i++) {
+  for (int i = 0; i < half_fcc_nn; i++) {
     rchi[0] = Rchi[i][0];
     rchi[1] = Rchi[i][1];
     rchi[2] = Rchi[i][2];
diff --git a/src/ORIENT/fix_orient_fcc.h b/src/ORIENT/fix_orient_fcc.h
index 6791672326..dd36a89547 100644
--- a/src/ORIENT/fix_orient_fcc.h
+++ b/src/ORIENT/fix_orient_fcc.h
@@ -69,9 +69,9 @@ class FixOrientFCC : public Fix {
   char *xifilename, *chifilename;    // file names for 2 crystal orientations
 
   bool use_xismooth;
-  double Rxi[8][3] = {0}, Rchi[8][3] = {0}, half_xi_chi_vec[2][4][3] = {0};
+  static constexpr int half_fcc_nn = 6;
+  double Rxi[half_fcc_nn][3] = {}, Rchi[half_fcc_nn][3] = {}, half_xi_chi_vec[2][half_fcc_nn][3] = {};
   double xiid, xi0, xi1, xicutoffsq, cutsq, added_energy;
-  int half_fcc_nn;
 
   int nmax;          // expose 2 per-atom quantities
   double **order;    // order param and normalized order param