diff --git a/src/BODY/body_nparticle.cpp b/src/BODY/body_nparticle.cpp
index 696ebcce7d..a3ffc9a5b5 100644
--- a/src/BODY/body_nparticle.cpp
+++ b/src/BODY/body_nparticle.cpp
@@ -21,6 +21,7 @@
 #include "force.h"
 #include "memory.h"
 #include "error.h"
+#include "fmt/format.h"
 
 using namespace LAMMPS_NS;
 
@@ -192,6 +193,92 @@ void BodyNparticle::data_body(int ibonus, int ninteger, int ndouble,
   }
 }
 
+/* ----------------------------------------------------------------------
+   pack data struct for one body into buf for writing to data file
+   if buf is NULL, just return buffer size
+------------------------------------------------------------------------- */
+
+int BodyNparticle::pack_data_body(tagint atomID, int ibonus, double *buf)
+{
+  int m;
+  double values[3],p[3][3],pdiag[3][3],ispace[3][3];
+
+  AtomVecBody::Bonus *bonus = &avec->bonus[ibonus];
+
+  double *quat = bonus->quat;
+  double *inertia = bonus->inertia;
+  int *ivalue = bonus->ivalue;
+  double *dvalue = bonus->dvalue;
+
+  int nsub = ivalue[0];
+
+  if (buf) {
+    
+    // ID ninteger ndouble
+
+    m = 0;
+    buf[m++] = ubuf(atomID).d;
+    buf[m++] = ubuf(1).d;
+    buf[m++] = ubuf(6 + 3*nsub).d;
+
+    // single integer Nsub
+    
+    buf[m++] = ubuf(nsub).d;
+
+    // 6 moments of inertia
+
+    MathExtra::quat_to_mat(quat,p);
+    MathExtra::times3_diag(p,inertia,pdiag);
+    MathExtra::times3_transpose(pdiag,p,ispace);
+
+    buf[m++] = ispace[0][0];
+    buf[m++] = ispace[1][1];
+    buf[m++] = ispace[2][2];
+    buf[m++] = ispace[0][1];
+    buf[m++] = ispace[0][2];
+    buf[m++] = ispace[1][2];
+
+    // 3*Nsub particle coords = displacement from COM in box frame
+    
+    for (int i = 0; i < nsub; i++) {
+      MathExtra::matvec(p,&dvalue[3*i],values);
+      buf[m++] = values[0];
+      buf[m++] = values[1];
+      buf[m++] = values[2];
+    }
+
+  } else m = 3 + 1 + 6 + 3*nsub;
+  
+  return m;
+}
+
+/* ----------------------------------------------------------------------
+   write info for one body to data file
+------------------------------------------------------------------------- */
+
+int BodyNparticle::write_data_body(FILE *fp, double *buf)
+{
+  int m = 0;
+
+  tagint atomID = (tagint) ubuf(buf[m++]).i;
+  int ninteger = (int) ubuf(buf[m++]).i;
+  int ndouble = (int) ubuf(buf[m++]).i;
+  fmt::print(fp,"{} {} {}\n",atomID,ninteger,ndouble);
+
+  int nsub = (int) ubuf(buf[m++]).i;
+  fmt::print(fp,"{}\n",nsub);
+
+  double *inertia = &buf[m];
+  fmt::print(fp,"{} {} {} {} {} {}\n",
+	     inertia[0],inertia[1],inertia[2],inertia[3],inertia[4],inertia[5]);
+  m += 6;
+  
+  for (int i = 0; i < nsub; i++)
+    fmt::print(fp,"{} {} {}\n",buf[m++],buf[m++],buf[m++]);
+  
+  return m;
+}
+
 /* ----------------------------------------------------------------------
    return radius of body particle defined by ifile/dfile params
    params are ordered as in data file
diff --git a/src/BODY/body_nparticle.h b/src/BODY/body_nparticle.h
index 46903f9657..c598fc8086 100644
--- a/src/BODY/body_nparticle.h
+++ b/src/BODY/body_nparticle.h
@@ -35,6 +35,8 @@ class BodyNparticle : public Body {
   int pack_border_body(struct AtomVecBody::Bonus *, double *);
   int unpack_border_body(struct AtomVecBody::Bonus *, double *);
   void data_body(int, int, int, int *, double *);
+  int pack_data_body(tagint, int, double *);
+  int write_data_body(FILE *, double *);
   double radius_body(int, int, int *, double *);
 
   int noutrow(int);
diff --git a/src/BODY/body_rounded_polygon.cpp b/src/BODY/body_rounded_polygon.cpp
index d855c5aea7..0fff73e435 100644
--- a/src/BODY/body_rounded_polygon.cpp
+++ b/src/BODY/body_rounded_polygon.cpp
@@ -320,6 +320,26 @@ void BodyRoundedPolygon::data_body(int ibonus, int ninteger, int ndouble,
   }
 }
 
+/* ----------------------------------------------------------------------
+   pack data struct for one body into buf for writing to data file
+   if buf is NULL, just return buffer size
+------------------------------------------------------------------------- */
+
+int BodyRoundedPolygon::pack_data_body(tagint atomID, int ibonus, double *buf)
+{
+  AtomVecBody::Bonus *bonus = &avec->bonus[ibonus];
+  return 0;
+}
+
+/* ----------------------------------------------------------------------
+   write info for one body to data file
+------------------------------------------------------------------------- */
+
+int BodyRoundedPolygon::write_data_body(FILE *fp, double *buf)
+{
+  return 0;
+}
+
 /* ----------------------------------------------------------------------
    return radius of body particle defined by ifile/dfile params
    params are ordered as in data file
diff --git a/src/BODY/body_rounded_polygon.h b/src/BODY/body_rounded_polygon.h
index b6f45c5cf5..f5129418c4 100644
--- a/src/BODY/body_rounded_polygon.h
+++ b/src/BODY/body_rounded_polygon.h
@@ -39,6 +39,8 @@ class BodyRoundedPolygon : public Body {
   int pack_border_body(struct AtomVecBody::Bonus *, double *);
   int unpack_border_body(struct AtomVecBody::Bonus *, double *);
   void data_body(int, int, int, int *, double *);
+  int pack_data_body(tagint, int, double *);
+  int write_data_body(FILE *, double *);
   double radius_body(int, int, int *, double *);
 
   int noutrow(int);
diff --git a/src/BODY/body_rounded_polyhedron.cpp b/src/BODY/body_rounded_polyhedron.cpp
index a82404ab15..0c8656dfd1 100644
--- a/src/BODY/body_rounded_polyhedron.cpp
+++ b/src/BODY/body_rounded_polyhedron.cpp
@@ -378,6 +378,26 @@ void BodyRoundedPolyhedron::data_body(int ibonus, int ninteger, int ndouble,
   }
 }
 
+/* ----------------------------------------------------------------------
+   pack data struct for one body into buf for writing to data file
+   if buf is NULL, just return buffer size
+------------------------------------------------------------------------- */
+
+int BodyRoundedPolyhedron::pack_data_body(tagint atomID, int ibonus, double *buf)
+{
+  AtomVecBody::Bonus *bonus = &avec->bonus[ibonus];
+  return 0;
+}
+
+/* ----------------------------------------------------------------------
+   write info for one body to data file
+------------------------------------------------------------------------- */
+
+int BodyRoundedPolyhedron::write_data_body(FILE *fp, double *buf)
+{
+  return 0;
+}
+
 /* ----------------------------------------------------------------------
    return radius of body particle defined by ifile/dfile params
    params are ordered as in data file
diff --git a/src/BODY/body_rounded_polyhedron.h b/src/BODY/body_rounded_polyhedron.h
index e5b15fd8f9..5aead799c3 100644
--- a/src/BODY/body_rounded_polyhedron.h
+++ b/src/BODY/body_rounded_polyhedron.h
@@ -41,6 +41,8 @@ class BodyRoundedPolyhedron : public Body {
   int pack_border_body(struct AtomVecBody::Bonus *, double *);
   int unpack_border_body(struct AtomVecBody::Bonus *, double *);
   void data_body(int, int, int, int *, double *);
+  int pack_data_body(tagint, int, double *);
+  int write_data_body(FILE *, double *);
   double radius_body(int, int, int *, double *);
 
   int noutrow(int);
diff --git a/src/atom_vec.cpp b/src/atom_vec.cpp
index 1d2c99dd17..d3c336769b 100644
--- a/src/atom_vec.cpp
+++ b/src/atom_vec.cpp
@@ -2304,16 +2304,6 @@ void AtomVec::write_improper(FILE *fp, int n, tagint **buf, int index)
   }
 }
 
-/* ----------------------------------------------------------------------
-   return size_data_bonus
-   only AtomVecHybrid overrides this, so it can select which bonus data via flag
-------------------------------------------------------------------------- */
-
-int AtomVec::size_data_bonus_query(int /*flag*/)
-{
-  return size_data_bonus;
-}
-
 /* ----------------------------------------------------------------------
    return # of bytes of allocated memory
 ------------------------------------------------------------------------- */
diff --git a/src/atom_vec.h b/src/atom_vec.h
index 71057848a2..07dec63506 100644
--- a/src/atom_vec.h
+++ b/src/atom_vec.h
@@ -145,9 +145,8 @@ class AtomVec : protected Pointers {
   virtual int pack_improper(tagint **);
   virtual void write_improper(FILE *, int, tagint **, int);
 
-  virtual int size_data_bonus_query(int);
-  virtual int pack_data_bonus(double **, int) {return 0;}
-  virtual void write_data_bonus(FILE *, int, double **, int) {}
+  virtual int pack_data_bonus(double *, int) {return 0;}
+  virtual void write_data_bonus(FILE *, int, double *, int) {}
 
   virtual int property_atom(char *) {return -1;}
   virtual void pack_property_atom(int, double *, int, int) {}
diff --git a/src/atom_vec_body.cpp b/src/atom_vec_body.cpp
index 18312482d1..04522882f9 100644
--- a/src/atom_vec_body.cpp
+++ b/src/atom_vec_body.cpp
@@ -581,28 +581,22 @@ void AtomVecBody::pack_data_pre(int ilocal)
 
 /* ----------------------------------------------------------------------
    pack bonus body info for writing to data file
-   if buf is NULL, just return count of bodies
+   if buf is NULL, just return buffer size
 ------------------------------------------------------------------------- */
 
-int AtomVecBody::pack_data_bonus(double **buf, int /*flag*/)
+int AtomVecBody::pack_data_bonus(double *buf, int /*flag*/)
 {
   int i,j;
   
   tagint *tag = atom->tag;
   int nlocal = atom->nlocal;
 
-  // NOTE: needs to call Body sub-class to fill buffer
-
   int m = 0;
   for (i = 0; i < nlocal; i++) {
     if (body[i] < 0) continue;
-    if (buf) {
-      buf[m][0] = ubuf(tag[i]).d;
-      j = body[i];
-    }
-    m++;
+    m += bptr->pack_data_body(tag[i],body[i],buf);
   }
-
+  
   return m;
 }
 
@@ -610,11 +604,11 @@ int AtomVecBody::pack_data_bonus(double **buf, int /*flag*/)
    write bonus body info to data file
 ------------------------------------------------------------------------- */
 
-void AtomVecBody::write_data_bonus(FILE *fp, int n, double **buf, int /*flag*/)
+void AtomVecBody::write_data_bonus(FILE *fp, int n, double *buf, int /*flag*/)
 {
-  // NOTE: needs to call Body sub-class to do the write
-  
-  for (int i = 0; i < n; i++) {
+  int i = 0;
+  while (i < n) {
+    i += bptr->write_data_body(fp,&buf[i]);
   }
 }
 
diff --git a/src/atom_vec_body.h b/src/atom_vec_body.h
index 04838074d9..809d90c25f 100644
--- a/src/atom_vec_body.h
+++ b/src/atom_vec_body.h
@@ -63,8 +63,8 @@ class AtomVecBody : public AtomVec {
   void pack_data_pre(int);
   void pack_data_post(int);
 
-  int pack_data_bonus(double **, int);
-  void write_data_bonus(FILE *, int, double **, int);
+  int pack_data_bonus(double *, int);
+  void write_data_bonus(FILE *, int, double *, int);
 
   // methods used by other classes to query/set body info
 
diff --git a/src/atom_vec_ellipsoid.cpp b/src/atom_vec_ellipsoid.cpp
index 4190f9ff6e..2f072736fd 100644
--- a/src/atom_vec_ellipsoid.cpp
+++ b/src/atom_vec_ellipsoid.cpp
@@ -484,10 +484,10 @@ void AtomVecEllipsoid::pack_data_post(int ilocal)
 
 /* ----------------------------------------------------------------------
    pack bonus ellipsoid info for writing to data file
-   if buf is NULL, just return count of ellipsoids
+   if buf is NULL, just return buffer size
 ------------------------------------------------------------------------- */
 
-int AtomVecEllipsoid::pack_data_bonus(double **buf, int /*flag*/)
+int AtomVecEllipsoid::pack_data_bonus(double *buf, int /*flag*/)
 {
   int i,j;
   
@@ -498,17 +498,16 @@ int AtomVecEllipsoid::pack_data_bonus(double **buf, int /*flag*/)
   for (i = 0; i < nlocal; i++) {
     if (ellipsoid[i] < 0) continue;
     if (buf) {
-      buf[m][0] = ubuf(tag[i]).d;
+      buf[m++] = ubuf(tag[i]).d;
       j = ellipsoid[i];
-      buf[m][1] = bonus[j].shape[0];
-      buf[m][2] = bonus[j].shape[1];
-      buf[m][3] = bonus[j].shape[2];
-      buf[m][4] = bonus[j].quat[0];
-      buf[m][5] = bonus[j].quat[1];
-      buf[m][6] = bonus[j].quat[2];
-      buf[m][7] = bonus[j].quat[3];
-    }
-    m++;
+      buf[m++] = bonus[j].shape[0];
+      buf[m++] = bonus[j].shape[1];
+      buf[m++] = bonus[j].shape[2];
+      buf[m++] = bonus[j].quat[0];
+      buf[m++] = bonus[j].quat[1];
+      buf[m++] = bonus[j].quat[2];
+      buf[m++] = bonus[j].quat[3];
+    } else m += size_data_bonus;
   }
 
   return m;
@@ -518,12 +517,14 @@ int AtomVecEllipsoid::pack_data_bonus(double **buf, int /*flag*/)
    write bonus ellipsoid info to data file
 ------------------------------------------------------------------------- */
 
-void AtomVecEllipsoid::write_data_bonus(FILE *fp, int n, double **buf, int /*flag*/)
+void AtomVecEllipsoid::write_data_bonus(FILE *fp, int n, double *buf, int /*flag*/)
 {
-  for (int i = 0; i < n; i++) {
-    fmt::print(fp,"{} {} {} {} {} {} {} {}",
-	       (tagint) ubuf(buf[i][0]).i,buf[i][1],buf[i][2],buf[i][3],
-	       buf[i][4],buf[i][5],buf[i][6],buf[i][7]);
+  int i = 0;
+  while (i < n) {
+    fmt::print(fp,"{} {} {} {} {} {} {} {}\n",
+	       (tagint) ubuf(buf[i]).i,
+	       buf[i+1],buf[i+2],buf[i+3],buf[i+4],buf[i+5],buf[i+6],buf[i+7]);
+    i += size_data_bonus;
   }
 }
 
diff --git a/src/atom_vec_ellipsoid.h b/src/atom_vec_ellipsoid.h
index 91191d5f48..a7961f97f8 100644
--- a/src/atom_vec_ellipsoid.h
+++ b/src/atom_vec_ellipsoid.h
@@ -56,8 +56,8 @@ class AtomVecEllipsoid : public AtomVec {
   void pack_data_pre(int);
   void pack_data_post(int);
 
-  int pack_data_bonus(double **, int);
-  void write_data_bonus(FILE *, int, double **, int);
+  int pack_data_bonus(double *, int);
+  void write_data_bonus(FILE *, int, double *, int);
   
   // unique to AtomVecEllipsoid
 
diff --git a/src/atom_vec_hybrid.cpp b/src/atom_vec_hybrid.cpp
index 2548287f07..d0ae1c37bb 100644
--- a/src/atom_vec_hybrid.cpp
+++ b/src/atom_vec_hybrid.cpp
@@ -459,55 +459,34 @@ void AtomVecHybrid::pack_data_post(int ilocal)
 }
 
 /* ----------------------------------------------------------------------
-   return size_data_bonus
-   match flag to sub-style
+   pack bonus info for writing to data file, match flag to sub-style
 ------------------------------------------------------------------------- */
 
-int AtomVecHybrid::size_data_bonus_query(int flag)
+int AtomVecHybrid::pack_data_bonus(double *buf, int flag)
 {
   for (int k = 0; k < nstyles; k++) {
-    if (flag == ELLIPSOID && strcmp(keywords[k],"ellipsoid") == 0)
-      return styles[k]->size_data_bonus;
-    if (flag == LINE && strcmp(keywords[k],"line") == 0)
-      return styles[k]->size_data_bonus;
-    if (flag == TRIANGLE && strcmp(keywords[k],"tri") == 0)
-      return styles[k]->size_data_bonus;
-    // this will not work, body style does not set size_data_bonus
-    // if (flag == BODY && strcmp(keywords[k],"body") == 0)
-    //   return styles[k]->size_data_bonus;
+    if (flag == ELLIPSOID && strcmp(keywords[k],"ellipsoid") != 0) continue;
+    if (flag == LINE && strcmp(keywords[k],"line") != 0) continue;
+    if (flag == TRIANGLE && strcmp(keywords[k],"tri") != 0) continue;
+    if (flag == BODY && strcmp(keywords[k],"body") != 0) continue;
+    
+    return styles[k]->pack_data_bonus(buf,flag);
   }
 }
 
 /* ----------------------------------------------------------------------
-   pack bonus info for writing to data file
-   match flag to sub-style
+   write bonus info to data file, match flag to sub-style
 ------------------------------------------------------------------------- */
 
-int AtomVecHybrid::pack_data_bonus(double **buf, int flag)
+void AtomVecHybrid::write_data_bonus(FILE *fp, int n, double *buf, int flag)
 {
   for (int k = 0; k < nstyles; k++) {
-    if (flag == ELLIPSOID && strcmp(keywords[k],"ellipsoid") == 0)
-      return styles[k]->pack_data_bonus(buf,flag);
-    if (flag == LINE && strcmp(keywords[k],"line") == 0)
-      return styles[k]->pack_data_bonus(buf,flag);
-    if (flag == TRIANGLE && strcmp(keywords[k],"tri") == 0)
-      return styles[k]->pack_data_bonus(buf,flag);
-  }
-}
+    if (flag == ELLIPSOID && strcmp(keywords[k],"ellipsoid") != 0) continue;
+    if (flag == LINE && strcmp(keywords[k],"line") != 0) continue;
+    if (flag == TRIANGLE && strcmp(keywords[k],"tri") != 0) continue;
+    if (flag == BODY && strcmp(keywords[k],"body") != 0) continue;
 
-/* ----------------------------------------------------------------------
-   write bonus info to data file
-------------------------------------------------------------------------- */
-
-void AtomVecHybrid::write_data_bonus(FILE *fp, int n, double **buf, int flag)
-{
-  for (int k = 0; k < nstyles; k++) { 
-    if (flag == ELLIPSOID && strcmp(keywords[k],"ellipsoid") == 0)
-      styles[k]->write_data_bonus(fp,n,buf,flag);
-    if (flag == LINE && strcmp(keywords[k],"line") == 0)
-      styles[k]->write_data_bonus(fp,n,buf,flag);
-    if (flag == TRIANGLE && strcmp(keywords[k],"tri") == 0)
-      styles[k]->write_data_bonus(fp,n,buf,flag);
+    styles[k]->write_data_bonus(fp,n,buf,flag);
   }
 }
 
diff --git a/src/atom_vec_hybrid.h b/src/atom_vec_hybrid.h
index ff4f168214..00be1b0418 100644
--- a/src/atom_vec_hybrid.h
+++ b/src/atom_vec_hybrid.h
@@ -58,9 +58,8 @@ class AtomVecHybrid : public AtomVec {
   void pack_data_pre(int);
   void pack_data_post(int);
 
-  int size_data_bonus_query(int);
-  int pack_data_bonus(double **, int);
-  void write_data_bonus(FILE *, int, double **, int);
+  int pack_data_bonus(double *, int);
+  void write_data_bonus(FILE *, int, double *, int);
 
   int property_atom(char *);
   void pack_property_atom(int, double *, int, int);
diff --git a/src/atom_vec_line.cpp b/src/atom_vec_line.cpp
index 6a368fe2da..f6e42933fc 100644
--- a/src/atom_vec_line.cpp
+++ b/src/atom_vec_line.cpp
@@ -457,10 +457,10 @@ void AtomVecLine::pack_data_post(int ilocal)
 
 /* ----------------------------------------------------------------------
    pack bonus line info for writing to data file
-   if buf is NULL, just return count of lines
+   if buf is NULL, just return buffer size
 ------------------------------------------------------------------------- */
 
-int AtomVecLine::pack_data_bonus(double **buf, int /*flag*/)
+int AtomVecLine::pack_data_bonus(double *buf, int /*flag*/)
 {
   int i,j;
   double length,theta;
@@ -474,7 +474,7 @@ int AtomVecLine::pack_data_bonus(double **buf, int /*flag*/)
   for (i = 0; i < nlocal; i++) {
     if (line[i] < 0) continue;
     if (buf) {
-      buf[m][0] = ubuf(tag[i]).d;
+      buf[m++] = ubuf(tag[i]).d;
       j = line[i];
       length = bonus[j].length;
       theta = bonus[j].theta;
@@ -484,12 +484,11 @@ int AtomVecLine::pack_data_bonus(double **buf, int /*flag*/)
       y1 = yc - 0.5*sin(theta)*length;
       x2 = xc + 0.5*cos(theta)*length;
       y2 = yc + 0.5*sin(theta)*length;
-      buf[m][1] = x1;
-      buf[m][2] = y1;
-      buf[m][3] = x2;
-      buf[m][4] = y2;
-    }
-    m++;
+      buf[m++] = x1;
+      buf[m++] = y1;
+      buf[m++] = x2;
+      buf[m++] = y2;
+    } else m += size_data_bonus;
   }
 
   return m;
@@ -499,12 +498,13 @@ int AtomVecLine::pack_data_bonus(double **buf, int /*flag*/)
    write bonus line info to data file
 ------------------------------------------------------------------------- */
 
-void AtomVecLine::write_data_bonus(FILE *fp, int n, double **buf, int /*flag*/)
+void AtomVecLine::write_data_bonus(FILE *fp, int n, double *buf, int /*flag*/)
 {
-  for (int i = 0; i < n; i++) {
-    fmt::print(fp,"{} {} {} {} {}",
-	       (tagint) ubuf(buf[i][0]).i,
-	       buf[i][1],buf[i][2],buf[i][3],buf[i][4]);
+  int i = 0;
+  while (i < n) {
+    fmt::print(fp,"{} {} {} {} {}\n",
+	       (tagint) ubuf(buf[i]).i,buf[i+1],buf[i+2],buf[i+3],buf[i+4]);
+    i += size_data_bonus;
   }
 }
 
diff --git a/src/atom_vec_line.h b/src/atom_vec_line.h
index e5e32c06bf..55a4b8bc02 100644
--- a/src/atom_vec_line.h
+++ b/src/atom_vec_line.h
@@ -56,8 +56,8 @@ class AtomVecLine : public AtomVec {
   void pack_data_pre(int);
   void pack_data_post(int);
 
-  int pack_data_bonus(double **, int);
-  void write_data_bonus(FILE *, int, double **, int);
+  int pack_data_bonus(double *, int);
+  void write_data_bonus(FILE *, int, double *, int);
 
   // unique to AtomVecLine
 
diff --git a/src/atom_vec_tri.cpp b/src/atom_vec_tri.cpp
index 16183995fe..29b996dae1 100644
--- a/src/atom_vec_tri.cpp
+++ b/src/atom_vec_tri.cpp
@@ -688,10 +688,10 @@ void AtomVecTri::pack_data_post(int ilocal)
 
 /* ----------------------------------------------------------------------
    pack bonus tri info for writing to data file
-   if buf is NULL, just return count of lines
+   if buf is NULL, just return buffer size
 ------------------------------------------------------------------------- */
 
-int AtomVecTri::pack_data_bonus(double **buf, int /*flag*/)
+int AtomVecTri::pack_data_bonus(double *buf, int /*flag*/)
 {
   int i,j;
   double xc,yc,zc;
@@ -706,7 +706,7 @@ int AtomVecTri::pack_data_bonus(double **buf, int /*flag*/)
   for (i = 0; i < nlocal; i++) {
     if (tri[i] < 0) continue;
     if (buf) {
-      buf[m][0] = ubuf(tag[i]).d;
+      buf[m++] = ubuf(tag[i]).d;
       j = tri[i];
       MathExtra::quat_to_mat(bonus[j].quat,p);
       MathExtra::matvec(p,bonus[j].c1,dc1);
@@ -715,15 +715,15 @@ int AtomVecTri::pack_data_bonus(double **buf, int /*flag*/)
       xc = x[i][0];
       yc = x[i][1];
       zc = x[i][2];
-      buf[m][1] = xc + dc1[0];
-      buf[m][2] = yc + dc1[1];
-      buf[m][3] = zc + dc1[2];
-      buf[m][4] = xc + dc2[0];
-      buf[m][5] = yc + dc2[1];
-      buf[m][6] = zc + dc2[2];
-      buf[m][7] = xc + dc3[0];
-      buf[m][8] = yc + dc3[1];
-      buf[m][9] = zc + dc3[2];
+      buf[m++] = xc + dc1[0];
+      buf[m++] = yc + dc1[1];
+      buf[m++] = zc + dc1[2];
+      buf[m++] = xc + dc2[0];
+      buf[m++] = yc + dc2[1];
+      buf[m++] = zc + dc2[2];
+      buf[m++] = xc + dc3[0];
+      buf[m++] = yc + dc3[1];
+      buf[m++] = zc + dc3[2];
     }
     m++;
   }
@@ -735,14 +735,14 @@ int AtomVecTri::pack_data_bonus(double **buf, int /*flag*/)
    write bonus tri info to data file
 ------------------------------------------------------------------------- */
 
-void AtomVecTri::write_data_bonus(FILE *fp, int n, double **buf, int /*flag*/)
+void AtomVecTri::write_data_bonus(FILE *fp, int n, double *buf, int /*flag*/)
 {
-  for (int i = 0; i < n; i++) {
-    fmt::print(fp,"{} {} {} {} {} {} {} {} {} {} {}",
-	       (tagint) ubuf(buf[i][0]).i,
-	       buf[i][1],buf[i][2],buf[i][3],
-	       buf[i][4],buf[i][5],buf[i][6],
-	       buf[i][7],buf[i][8],buf[i][9]);
+  int i = 0;
+  while (i < n) {
+    fmt::print(fp,"{} {} {} {} {} {} {} {} {} {} {}\n",
+	       (tagint) ubuf(buf[i]).i,buf[i+1],buf[i+2],buf[i+3],
+	       buf[i+4],buf[i+5],buf[i+6],buf[i+7],buf[i+8],buf[i+9]);
+    i += size_data_bonus;
   }
 }
 
diff --git a/src/atom_vec_tri.h b/src/atom_vec_tri.h
index cbdbc73290..9becf315f6 100644
--- a/src/atom_vec_tri.h
+++ b/src/atom_vec_tri.h
@@ -58,8 +58,8 @@ class AtomVecTri : public AtomVec {
   void pack_data_pre(int);
   void pack_data_post(int);
 
-  int pack_data_bonus(double **, int);
-  void write_data_bonus(FILE *, int, double **, int);
+  int pack_data_bonus(double *, int);
+  void write_data_bonus(FILE *, int, double *, int);
 
   // unique to AtomVecTri
 
diff --git a/src/body.h b/src/body.h
index 8cb4039f9d..e843c21b40 100644
--- a/src/body.h
+++ b/src/body.h
@@ -43,6 +43,9 @@ class Body : protected Pointers {
                                  double *) {return 0;}
 
   virtual void data_body(int, int, int, int*, double *) = 0;
+  virtual int pack_data_body(tagint, int, double *) = 0;
+  virtual int write_data_body(FILE *, double *) = 0;
+ 
   virtual int noutrow(int) = 0;
   virtual int noutcol() = 0;
   virtual void output(int, int, double *) = 0;
diff --git a/src/write_data.cpp b/src/write_data.cpp
index 8567325058..60d3781ff5 100644
--- a/src/write_data.cpp
+++ b/src/write_data.cpp
@@ -658,16 +658,15 @@ void WriteData::impropers()
 void WriteData::bonus(int flag)
 {
   // communication buffer for all my Bonus info
-  // maxrow X ncol = largest buffer needed by any proc
+  // maxvalues = largest buffer needed by any proc
 
-  int ncol = atom->avec->size_data_bonus_query(flag);
-  int sendrow = atom->avec->pack_data_bonus(NULL,flag);
-  int maxrow;
-  MPI_Allreduce(&sendrow,&maxrow,1,MPI_INT,MPI_MAX,world);
+  int nvalues = atom->avec->pack_data_bonus(NULL,flag);
+  int maxvalues;
+  MPI_Allreduce(&nvalues,&maxvalues,1,MPI_INT,MPI_MAX,world);
 
-  double **buf;
-  if (me == 0) memory->create(buf,MAX(1,maxrow),ncol,"write_data:buf");
-  else memory->create(buf,MAX(1,sendrow),ncol,"write_data:buf");
+  double *buf;
+  if (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
 
@@ -690,19 +689,18 @@ void WriteData::bonus(int flag)
     
     for (int iproc = 0; iproc < nprocs; iproc++) {
       if (iproc) {
-        MPI_Irecv(&buf[0][0],maxrow*ncol,MPI_DOUBLE,iproc,0,world,&request);
+        MPI_Irecv(buf,maxvalues,MPI_DOUBLE,iproc,0,world,&request);
         MPI_Send(&tmp,0,MPI_INT,iproc,0,world);
         MPI_Wait(&request,&status);
-        MPI_Get_count(&status,MPI_DOUBLE,&recvrow);
-        recvrow /= ncol;
-      } else recvrow = sendrow;
+        MPI_Get_count(&status,MPI_DOUBLE,&nvalues);
+      }
 
-      atom->avec->write_data_bonus(fp,recvrow,buf,flag);
+      atom->avec->write_data_bonus(fp,nvalues,buf,flag);
     }
 
   } else {
     MPI_Recv(&tmp,0,MPI_INT,0,0,world,MPI_STATUS_IGNORE);
-    MPI_Rsend(&buf[0][0],sendrow*ncol,MPI_DOUBLE,0,0,world);
+    MPI_Rsend(buf,nvalues,MPI_DOUBLE,0,0,world);
   }
 
   memory->destroy(buf);