diff --git a/src/write_coeff.cpp b/src/write_coeff.cpp
new file mode 100644
index 0000000000..9158e0c842
--- /dev/null
+++ b/src/write_coeff.cpp
@@ -0,0 +1,109 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#include <string.h>
+#include <unistd.h>
+#include "write_coeff.h"
+#include "pair.h"
+#include "bond.h"
+#include "angle.h"
+#include "dihedral.h"
+#include "improper.h"
+#include "comm.h"
+#include "force.h"
+#include "universe.h"
+#include "error.h"
+
+using namespace LAMMPS_NS;
+
+/* ----------------------------------------------------------------------
+   called as write_coeff command in input script
+------------------------------------------------------------------------- */
+
+void WriteCoeff::command(int narg, char **arg)
+{
+  if (domain->box_exist == 0)
+    error->all(FLERR,"write_coeff command before simulation box is defined");
+
+  if (narg != 1) error->all(FLERR,"Illegal write_coeff command");
+
+  int n = strlen(arg[0]) + 5;
+  char *file = new char[n];
+
+  strcpy(file,"tmp.");
+  strcat(file,arg[0]);
+
+  if (comm->me == 0) {
+    char str[256], coeff[256];
+    FILE *one = fopen(file,"wb+");
+    if (one == NULL) {
+          sprintf(str,"Cannot open coeff file %s",file);
+      error->one(FLERR,str);
+    }
+
+    if (force->pair && force->pair->writedata) {
+      force->pair->init();
+      fprintf(one,"# pair_style %s\npair_coeff\n",force->pair_style);
+      force->pair->write_data_all(one);
+      fprintf(one,"end\n");
+    }
+    if (force->bond && force->bond->writedata) {
+      fprintf(one,"# bond_style %s\nbond_coeff\n",force->bond_style);
+      force->bond->write_data(one);
+      fprintf(one,"end\n");
+    }
+    if (force->angle && force->angle->writedata) {
+      fprintf(one,"# angle_style %s\nangle_coeff\n",force->angle_style);
+      force->angle->write_data(one);
+      fprintf(one,"end\n");
+    }
+    if (force->dihedral && force->dihedral->writedata) {
+      fprintf(one,"# dihedral_style %s\ndihedral_coeff\n",force->dihedral_style);
+      force->dihedral->write_data(one);
+      fprintf(one,"end\n");
+    }
+    if (force->improper && force->improper->writedata) {
+      fprintf(one,"# improper_style %s\nimproper_coeff\n",force->improper_style);
+      force->improper->write_data(one);
+      fprintf(one,"end\n");
+    }
+    rewind(one);
+
+    FILE *two = fopen(file+4,"w");
+    if (two == NULL) {
+      sprintf(str,"Cannot open coeff file %s",file+4);
+      error->one(FLERR,str);
+    }
+    fprintf(two,"# LAMMPS coeff file via write_coeff, version %s\n",
+            universe->version);
+    while(1) {
+      if (fgets(str,256,one) == NULL) break;
+      fputs(str,two);      // style
+      fgets(str,256,one);  // coeff
+      n = strlen(str);
+      strcpy(coeff,str);
+      coeff[n-1] = '\0';
+      fgets(str,256,one);
+      while (strcmp(str,"end\n") != 0) {
+        fprintf(two,"%s %s",coeff,str);
+        fgets(str,256,one);
+      }
+      fputc('\n',two);
+    }
+    fclose(one);
+    fclose(two);
+    unlink(file);
+  }
+
+  delete [] file;
+}
diff --git a/src/write_coeff.h b/src/write_coeff.h
new file mode 100644
index 0000000000..9b272b40fc
--- /dev/null
+++ b/src/write_coeff.h
@@ -0,0 +1,61 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifdef COMMAND_CLASS
+
+CommandStyle(write_coeff,WriteCoeff)
+
+#else
+
+#ifndef LMP_WRITE_COEFF_H
+#define LMP_WRITE_COEFF_H
+
+#include <stdio.h>
+#include "pointers.h"
+
+namespace LAMMPS_NS {
+
+class WriteCoeff : protected Pointers {
+ public:
+  WriteCoeff(class LAMMPS *lmp) : Pointers(lmp) {};
+  void command(int, char **);
+};
+
+}
+
+#endif
+#endif
+
+/* ERROR/WARNING messages:
+
+E: write_coeff command before simulation box is defined
+
+Self-explanatory.
+
+E: Illegal ... command
+
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
+
+E: Atom count is inconsistent, cannot write data file
+
+The sum of atoms across processors does not equal the global number
+of atoms.  Probably some atoms have been lost.
+
+E: Cannot open coeff file %s
+
+The specified file cannot be opened.  Check that the path and name are
+correct.
+
+*/