diff --git a/src/write_data.cpp b/src/write_data.cpp
index bc6f1773d4..76d1c598ca 100644
--- a/src/write_data.cpp
+++ b/src/write_data.cpp
@@ -42,11 +42,7 @@ enum{ELLIPSOID,LINE,TRIANGLE,BODY};   // also in AtomVecHybrid
 
 /* ---------------------------------------------------------------------- */
 
-WriteData::WriteData(LAMMPS *lmp) : Command(lmp)
-{
-  MPI_Comm_rank(world,&me);
-  MPI_Comm_size(world,&nprocs);
-}
+WriteData::WriteData(LAMMPS *lmp) : Command(lmp) {}
 
 /* ----------------------------------------------------------------------
    called as write_data command in input script
@@ -74,12 +70,12 @@ void WriteData::command(int narg, char **arg)
   fixflag = 1;
   triclinic_general = 0;
   lmapflag = 1;
+  noinitflag = 0;
 
   // store current (default) setting since we may change it
 
   int domain_triclinic_general = domain->triclinic_general;
   int types_style = atom->types_style;
-  int noinit = 0;
 
   int iarg = 1;
   while (iarg < narg) {
@@ -90,7 +86,7 @@ void WriteData::command(int narg, char **arg)
       else error->all(FLERR,"Unknown write_data pair option: {}", arg[iarg+1]);
       iarg += 2;
     } else if (strcmp(arg[iarg],"noinit") == 0) {
-      noinit = 1;
+      noinitflag = 1;
       iarg++;
     } else if (strcmp(arg[iarg],"nocoeff") == 0) {
       coeffflag = 0;
@@ -130,7 +126,7 @@ void WriteData::command(int narg, char **arg)
   //     pair->init() can fail due to various unset values:
   //     e.g. pair hybrid coeffs, dpd ghost-atom velocity setting
 
-  if (noinit == 0) {
+  if (noinitflag == 0) {
     if (comm->me == 0) utils::logmesg(lmp,"System init for write_data ...\n");
     lmp->init();
 
@@ -206,7 +202,7 @@ void WriteData::write(const std::string &file)
 
   // open data file
 
-  if (me == 0) {
+  if (comm->me == 0) {
     fp = fopen(file.c_str(),"w");
     if (fp == nullptr)
       error->one(FLERR,"Cannot open data file {}: {}", file, utils::getsyserror());
@@ -215,7 +211,7 @@ void WriteData::write(const std::string &file)
   // proc 0 writes header, ntype-length arrays, force fields
   // label map must come before coeffs
 
-  if (me == 0) {
+  if (comm->me == 0) {
     header();
     if (lmapflag && atom->labelmapflag) atom->lmap->write_data(fp);
     type_arrays();
@@ -234,7 +230,7 @@ void WriteData::write(const std::string &file)
   if (atom->tag_enable) {
     if (natoms) velocities();
   } else {
-    if (me == 0)
+    if (comm->me == 0)
       error->warning(FLERR, "Not writing Velocities section of data file without atom IDs");
   }
 
@@ -269,7 +265,7 @@ void WriteData::write(const std::string &file)
 
   // close data file
 
-  if (me == 0) fclose(fp);
+  if (comm->me == 0) fclose(fp);
 }
 
 /* ----------------------------------------------------------------------
@@ -370,6 +366,15 @@ void WriteData::force_fields()
       fmt::print(fp,"\nPair Coeffs # {}\n\n", force->pair_style);
       force->pair->write_data(fp);
     } else if (pairflag == IJ) {
+      // try computing mixed pair coeffs in case we skipped lmp->init()
+      // this block of code is currently only accessed from LAMMPS-GUI's restart inspector
+      if (force->pair->allocated && noinitflag) {
+        if (comm->me == 0) error->warning(FLERR,"Computing missing pair coeffs from mixing");
+        for (int i=1; i < atom->ntypes; ++i)
+          for (int j=i; j <=atom->ntypes; ++j)
+            if (!force->pair->setflag[i][j])
+              force->pair->init_one(i, j);
+      }
       fmt::print(fp,"\nPairIJ Coeffs # {}\n\n", force->pair_style);
       force->pair->write_data_all(fp);
     }
@@ -407,7 +412,7 @@ void WriteData::atoms()
   MPI_Allreduce(&sendrow,&maxrow,1,MPI_INT,MPI_MAX,world);
 
   double **buf;
-  if (me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
+  if (comm->me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
   else memory->create(buf,MAX(1,sendrow),ncol,"write_data:buf");
 
   // pack my atom data into buf
@@ -420,12 +425,12 @@ void WriteData::atoms()
 
   int tmp,recvrow;
 
-  if (me == 0) {
+  if (comm->me == 0) {
     MPI_Status status;
     MPI_Request request;
 
     fmt::print(fp,"\nAtoms # {}\n\n",atom->atom_style);
-    for (int iproc = 0; iproc < nprocs; iproc++) {
+    for (int iproc = 0; iproc < comm->nprocs; iproc++) {
       if (iproc) {
         MPI_Irecv(&buf[0][0],maxrow*ncol,MPI_DOUBLE,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
@@ -460,7 +465,7 @@ void WriteData::velocities()
   MPI_Allreduce(&sendrow,&maxrow,1,MPI_INT,MPI_MAX,world);
 
   double **buf;
-  if (me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
+  if (comm->me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
   else memory->create(buf,MAX(1,sendrow),ncol,"write_data:buf");
 
   // pack my velocity data into buf
@@ -473,12 +478,12 @@ void WriteData::velocities()
 
   int tmp,recvrow;
 
-  if (me == 0) {
+  if (comm->me == 0) {
     MPI_Status status;
     MPI_Request request;
 
     fputs("\nVelocities\n\n",fp);
-    for (int iproc = 0; iproc < nprocs; iproc++) {
+    for (int iproc = 0; iproc < comm->nprocs; iproc++) {
       if (iproc) {
         MPI_Irecv(&buf[0][0],maxrow*ncol,MPI_DOUBLE,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
@@ -513,7 +518,7 @@ void WriteData::bonds()
   MPI_Allreduce(&sendrow,&maxrow,1,MPI_INT,MPI_MAX,world);
 
   tagint **buf;
-  if (me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
+  if (comm->me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
   else memory->create(buf,MAX(1,sendrow),ncol,"write_data:buf");
 
   // pack my bond data into buf
@@ -527,12 +532,12 @@ void WriteData::bonds()
   int tmp,recvrow;
 
   int index = 1;
-  if (me == 0) {
+  if (comm->me == 0) {
     MPI_Status status;
     MPI_Request request;
 
     fputs("\nBonds\n\n",fp);
-    for (int iproc = 0; iproc < nprocs; iproc++) {
+    for (int iproc = 0; iproc < comm->nprocs; iproc++) {
       if (iproc) {
         MPI_Irecv(&buf[0][0],maxrow*ncol,MPI_LMP_TAGINT,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
@@ -568,7 +573,7 @@ void WriteData::angles()
   MPI_Allreduce(&sendrow,&maxrow,1,MPI_INT,MPI_MAX,world);
 
   tagint **buf;
-  if (me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
+  if (comm->me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
   else memory->create(buf,MAX(1,sendrow),ncol,"write_data:buf");
 
   // pack my angle data into buf
@@ -582,12 +587,12 @@ void WriteData::angles()
   int tmp,recvrow;
 
   int index = 1;
-  if (me == 0) {
+  if (comm->me == 0) {
     MPI_Status status;
     MPI_Request request;
 
     fputs("\nAngles\n\n",fp);
-    for (int iproc = 0; iproc < nprocs; iproc++) {
+    for (int iproc = 0; iproc < comm->nprocs; iproc++) {
       if (iproc) {
         MPI_Irecv(&buf[0][0],maxrow*ncol,MPI_LMP_TAGINT,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
@@ -623,7 +628,7 @@ void WriteData::dihedrals()
   MPI_Allreduce(&sendrow,&maxrow,1,MPI_INT,MPI_MAX,world);
 
   tagint **buf;
-  if (me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
+  if (comm->me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
   else memory->create(buf,MAX(1,sendrow),ncol,"write_data:buf");
 
   // pack my dihedral data into buf
@@ -637,12 +642,12 @@ void WriteData::dihedrals()
   int tmp,recvrow;
 
   int index = 1;
-  if (me == 0) {
+  if (comm->me == 0) {
     MPI_Status status;
     MPI_Request request;
 
     fputs("\nDihedrals\n\n",fp);
-    for (int iproc = 0; iproc < nprocs; iproc++) {
+    for (int iproc = 0; iproc < comm->nprocs; iproc++) {
       if (iproc) {
         MPI_Irecv(&buf[0][0],maxrow*ncol,MPI_LMP_TAGINT,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
@@ -678,7 +683,7 @@ void WriteData::impropers()
   MPI_Allreduce(&sendrow,&maxrow,1,MPI_INT,MPI_MAX,world);
 
   tagint **buf;
-  if (me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
+  if (comm->me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
   else memory->create(buf,MAX(1,sendrow),ncol,"write_data:buf");
 
   // pack my improper data into buf
@@ -692,12 +697,12 @@ void WriteData::impropers()
   int tmp,recvrow;
 
   int index = 1;
-  if (me == 0) {
+  if (comm->me == 0) {
     MPI_Status status;
     MPI_Request request;
 
     fputs("\nImpropers\n\n",fp);
-    for (int iproc = 0; iproc < nprocs; iproc++) {
+    for (int iproc = 0; iproc < comm->nprocs; iproc++) {
       if (iproc) {
         MPI_Irecv(&buf[0][0],maxrow*ncol,MPI_LMP_TAGINT,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
@@ -733,7 +738,7 @@ void WriteData::bonus(int flag)
   MPI_Allreduce(&nvalues,&maxvalues,1,MPI_INT,MPI_MAX,world);
 
   double *buf = nullptr;
-  if (me == 0) memory->create(buf,MAX(1,maxvalues),"write_data:buf");
+  if (comm->me == 0) memory->create(buf,MAX(1,maxvalues),"write_data:buf");
   else memory->create(buf,MAX(1,nvalues),"write_data:buf");
 
   // pack my bonus data into buf
@@ -746,7 +751,7 @@ void WriteData::bonus(int flag)
 
   int tmp;
 
-  if (me == 0) {
+  if (comm->me == 0) {
     MPI_Status status;
     MPI_Request request;
 
@@ -755,7 +760,7 @@ void WriteData::bonus(int flag)
     if (flag == TRIANGLE)  fputs("\nTriangles\n\n",fp);
     if (flag == BODY)      fputs("\nBodies\n\n",fp);
 
-    for (int iproc = 0; iproc < nprocs; iproc++) {
+    for (int iproc = 0; iproc < comm->nprocs; iproc++) {
       if (iproc) {
         MPI_Irecv(buf,maxvalues,MPI_DOUBLE,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
@@ -789,7 +794,7 @@ void WriteData::fix(Fix *ifix, int mth)
   MPI_Allreduce(&sendrow,&maxrow,1,MPI_INT,MPI_MAX,world);
 
   double **buf;
-  if (me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
+  if (comm->me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
   else memory->create(buf,MAX(1,sendrow),ncol,"write_data:buf");
 
   // pack my fix data into buf
@@ -803,12 +808,12 @@ void WriteData::fix(Fix *ifix, int mth)
   int tmp,recvrow;
 
   int index = 1;
-  if (me == 0) {
+  if (comm->me == 0) {
     MPI_Status status;
     MPI_Request request;
 
     ifix->write_data_section_keyword(mth,fp);
-    for (int iproc = 0; iproc < nprocs; iproc++) {
+    for (int iproc = 0; iproc < comm->nprocs; iproc++) {
       if (iproc) {
         MPI_Irecv(&buf[0][0],maxrow*ncol,MPI_DOUBLE,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
diff --git a/src/write_data.h b/src/write_data.h
index ebaa97ffc0..b98fd6594d 100644
--- a/src/write_data.h
+++ b/src/write_data.h
@@ -31,12 +31,12 @@ class WriteData : public Command {
   void write(const std::string &);
 
  private:
-  int me, nprocs;
   int pairflag;
   int coeffflag;
   int fixflag;
   int triclinic_general;
   int lmapflag;
+  int noinitflag;
   FILE *fp;
   bigint nbonds_local, nbonds;
   bigint nangles_local, nangles;