diff --git a/src/pair_zhou.cpp b/src/pair_zhou.cpp
deleted file mode 100644
index fc5569574c..0000000000
--- a/src/pair_zhou.cpp
+++ /dev/null
@@ -1,361 +0,0 @@
-/* ----------------------------------------------------------------------
-   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 "math.h"
-#include "stdio.h"
-#include "stdlib.h"
-#include "pair_zhou.h"
-#include "atom.h"
-#include "comm.h"
-#include "force.h"
-#include "neigh_list.h"
-#include "memory.h"
-#include "error.h"
-
-using namespace LAMMPS_NS;
-
-/* ---------------------------------------------------------------------- */
-
-PairZhou::PairZhou(LAMMPS *lmp) : Pair(lmp) {}
-
-/* ---------------------------------------------------------------------- */
-
-PairZhou::~PairZhou()
-{
-  if (allocated) {
-    memory->destroy(setflag);
-    memory->destroy(cutsq);
-
-    memory->destroy(cut);
-    memory->destroy(d0);
-    memory->destroy(alpha);
-    memory->destroy(r0);
-    memory->destroy(c);
-    memory->destroy(rr);
-    memory->destroy(morse1);
-    memory->destroy(offset);
-  }
-}
-
-/* ---------------------------------------------------------------------- */
-
-void PairZhou::compute(int eflag, int vflag)
-{
-  int i,j,ii,jj,inum,jnum,itype,jtype;
-  double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;
-  double rsq,r,dr,dexp,factor_lj,r2inv,r6inv,ddexp,invexp;
-  int *ilist,*jlist,*numneigh,**firstneigh;
-
-  evdwl = 0.0;
-  if (eflag || vflag) ev_setup(eflag,vflag);
-  else evflag = vflag_fdotr = 0;
-
-  double **x = atom->x;
-  double **f = atom->f;
-  int *type = atom->type;
-  int nlocal = atom->nlocal;
-  double *special_lj = force->special_lj;
-  int newton_pair = force->newton_pair;
-
-  inum = list->inum;
-  ilist = list->ilist;
-  numneigh = list->numneigh;
-  firstneigh = list->firstneigh;
-  
-  // loop over neighbors of my atoms
-
-  for (ii = 0; ii < inum; ii++) {
-    i = ilist[ii];
-    xtmp = x[i][0];
-    ytmp = x[i][1];
-    ztmp = x[i][2];
-    itype = type[i];
-    jlist = firstneigh[i];
-    jnum = numneigh[i];
-
-    for (jj = 0; jj < jnum; jj++) {
-      j = jlist[jj];
-      factor_lj = special_lj[sbmask(j)];
-      j &= NEIGHMASK;
-
-      delx = xtmp - x[j][0];
-      dely = ytmp - x[j][1];
-      delz = ztmp - x[j][2];
-      rsq = delx*delx + dely*dely + delz*delz;
-      jtype = type[j];
-
-      if (rsq < cutsq[itype][jtype]) {
-        r2inv = 1.0/rsq;
-        r6inv = r2inv*r2inv*r2inv;
-	r = sqrt(rsq);
-	dr = r - r0[itype][jtype];
-	dexp = exp(-alpha[itype][jtype] * dr);
-        ddexp = exp(-dscale * (r/rr[itype][jtype] - 1.0));
-        invexp = 1.0/(1+ddexp);
-	fpair = morse1[itype][jtype] * (dexp*dexp - dexp) / r;
-        fpair -= sscale*c[itype][jtype] * (invexp*invexp*ddexp*(-dscale/rr[itype][jtype])*r6inv) / r;
-        fpair -= sscale*c[itype][jtype] * (6.0 * invexp * r6inv * r2inv);
-        fpair *= factor_lj;
-
-	f[i][0] += delx*fpair;
-	f[i][1] += dely*fpair;
-	f[i][2] += delz*fpair;
-	if (newton_pair || j < nlocal) {
-	  f[j][0] -= delx*fpair;
-	  f[j][1] -= dely*fpair;
-	  f[j][2] -= delz*fpair;
-	}
-
-	if (eflag) {
-	  evdwl = d0[itype][jtype] * (dexp*dexp - 2.0*dexp) -
-            sscale*c[itype][jtype]*r6inv*invexp  - offset[itype][jtype];
-	  evdwl *= factor_lj;
-	}
-
-	if (evflag) ev_tally(i,j,nlocal,newton_pair,
-			     evdwl,0.0,fpair,delx,dely,delz);
-      }
-    }
-  }
-
-  if (vflag_fdotr) virial_fdotr_compute();
-}
-
-/* ----------------------------------------------------------------------
-   allocate all arrays 
-------------------------------------------------------------------------- */
-
-void PairZhou::allocate()
-{
-  allocated = 1;
-  int n = atom->ntypes;
-
-  memory->create(setflag,n+1,n+1,"pair:setflag");
-  for (int i = 1; i <= n; i++)
-    for (int j = i; j <= n; j++)
-      setflag[i][j] = 0;
-
-  memory->create(cutsq,n+1,n+1,"pair:cutsq");
-
-  memory->create(cut,n+1,n+1,"pair:cut");
-  memory->create(d0,n+1,n+1,"pair:d0");
-  memory->create(alpha,n+1,n+1,"pair:alpha");
-  memory->create(r0,n+1,n+1,"pair:r0");
-  memory->create(c,n+1,n+1,"pair:c");
-  memory->create(rr,n+1,n+1,"pair:rr");
-  memory->create(morse1,n+1,n+1,"pair:morse1");
-  memory->create(offset,n+1,n+1,"pair:offset");
-}
-
-/* ----------------------------------------------------------------------
-   global settings 
-------------------------------------------------------------------------- */
-
-void PairZhou::settings(int narg, char **arg)
-{
-  if (narg != 3) error->all(FLERR,"Illegal pair_style command");
-
-  cut_global = force->numeric(FLERR,arg[0]);
-  sscale = force->numeric(FLERR,arg[1]);
-  dscale = force->numeric(FLERR,arg[2]);
-
-  // reset cutoffs that have been explicitly set
-
-  if (allocated) {
-    int i,j;
-    for (i = 1; i <= atom->ntypes; i++)
-      for (j = i+1; j <= atom->ntypes; j++)
-	if (setflag[i][j]) cut[i][j] = cut_global;
-  }
-}
-
-/* ----------------------------------------------------------------------
-   set coeffs for one or more type pairs
-------------------------------------------------------------------------- */
-
-void PairZhou::coeff(int narg, char **arg)
-{
-  if (narg < 7 || narg > 8) error->all(FLERR,"Incorrect args for pair coefficients");
-  if (!allocated) allocate();
-
-  int ilo,ihi,jlo,jhi;
-  force->bounds(FLERR,arg[0],atom->ntypes,ilo,ihi);
-  force->bounds(FLERR,arg[1],atom->ntypes,jlo,jhi);
-
-  double d0_one = force->numeric(FLERR,arg[2]);
-  double alpha_one = force->numeric(FLERR,arg[3]);
-  double r0_one = force->numeric(FLERR,arg[4]);
-  double c_one = force->numeric(FLERR,arg[5]);
-  double rr_one = force->numeric(FLERR,arg[6]);
-
-  double cut_one = cut_global;
-  if (narg == 8) cut_one = force->numeric(FLERR,arg[7]);
-
-  int count = 0;
-  for (int i = ilo; i <= ihi; i++) {
-    for (int j = MAX(jlo,i); j <= jhi; j++) {
-      d0[i][j] = d0_one;
-      alpha[i][j] = alpha_one;
-      r0[i][j] = r0_one;
-      cut[i][j] = cut_one;
-      c[i][j] = c_one;
-      rr[i][j] = rr_one;
-      setflag[i][j] = 1;
-      count++;
-    }
-  }
-
-  if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
-}
-
-
-/* ----------------------------------------------------------------------
-   init for one type pair i,j and corresponding j,i
-------------------------------------------------------------------------- */
-
-double PairZhou::init_one(int i, int j)
-{
-  if (setflag[i][j] == 0) error->all(FLERR,"All pair coeffs are not set");
-
-  morse1[i][j] = 2.0*d0[i][j]*alpha[i][j];
-     
-  if (offset_flag) {
-    double alpha_dr = -alpha[i][j] * (cut[i][j] - r0[i][j]);
-    offset[i][j] = d0[i][j] * (exp(2.0*alpha_dr) - 2.0*exp(alpha_dr));
-  } else offset[i][j] = 0.0;
-
-  d0[j][i] = d0[i][j];
-  alpha[j][i] = alpha[i][j];
-  r0[j][i] = r0[i][j];
-  c[j][i] = c[i][j];
-  rr[j][i] = rr[i][j];
-  morse1[j][i] = morse1[i][j];
-  offset[j][i] = offset[i][j];
-
-  return cut[i][j];
-}
-
-/* ----------------------------------------------------------------------
-   proc 0 writes to restart file
-------------------------------------------------------------------------- */
-
-void PairZhou::write_restart(FILE *fp)
-{
-  write_restart_settings(fp);
-
-  int i,j;
-  for (i = 1; i <= atom->ntypes; i++)
-    for (j = i; j <= atom->ntypes; j++) {
-      fwrite(&setflag[i][j],sizeof(int),1,fp);
-      if (setflag[i][j]) {
-	fwrite(&d0[i][j],sizeof(double),1,fp);
-	fwrite(&alpha[i][j],sizeof(double),1,fp);
-	fwrite(&r0[i][j],sizeof(double),1,fp);
-        fwrite(&c[i][j],sizeof(double),1,fp);
-        fwrite(&rr[i][j],sizeof(double),1,fp);
-	fwrite(&cut[i][j],sizeof(double),1,fp);
-      }
-    }
-}
-
-/* ----------------------------------------------------------------------
-   proc 0 reads from restart file, bcasts
-------------------------------------------------------------------------- */
-
-void PairZhou::read_restart(FILE *fp)
-{
-  read_restart_settings(fp);
-
-  allocate();
-
-  int i,j;
-  int me = comm->me;
-  for (i = 1; i <= atom->ntypes; i++)
-    for (j = i; j <= atom->ntypes; j++) {
-      if (me == 0) fread(&setflag[i][j],sizeof(int),1,fp);
-      MPI_Bcast(&setflag[i][j],1,MPI_INT,0,world);
-      if (setflag[i][j]) {
-	if (me == 0) {
-	  fread(&d0[i][j],sizeof(double),1,fp);
-	  fread(&alpha[i][j],sizeof(double),1,fp);
-	  fread(&r0[i][j],sizeof(double),1,fp);
-          fread(&c[i][j],sizeof(double),1,fp);
-          fread(&rr[i][j],sizeof(double),1,fp);
-	  fread(&cut[i][j],sizeof(double),1,fp);
-	}
-	MPI_Bcast(&d0[i][j],1,MPI_DOUBLE,0,world);
-	MPI_Bcast(&alpha[i][j],1,MPI_DOUBLE,0,world);
-	MPI_Bcast(&r0[i][j],1,MPI_DOUBLE,0,world);
-        MPI_Bcast(&c[i][j],1,MPI_DOUBLE,0,world);
-        MPI_Bcast(&rr[i][j],1,MPI_DOUBLE,0,world);
-	MPI_Bcast(&cut[i][j],1,MPI_DOUBLE,0,world);
-      }
-    }
-}
-
-/* ----------------------------------------------------------------------
-   proc 0 writes to restart file
-------------------------------------------------------------------------- */
-
-void PairZhou::write_restart_settings(FILE *fp)
-{
-  fwrite(&cut_global,sizeof(double),1,fp);
-  fwrite(&sscale,sizeof(double),1,fp);
-  fwrite(&dscale,sizeof(double),1,fp);
-  fwrite(&offset_flag,sizeof(int),1,fp);
-  fwrite(&mix_flag,sizeof(int),1,fp);
-}
-
-/* ----------------------------------------------------------------------
-   proc 0 reads from restart file, bcasts
-------------------------------------------------------------------------- */
-
-void PairZhou::read_restart_settings(FILE *fp)
-{
-  if (comm->me == 0) {
-    fread(&cut_global,sizeof(double),1,fp);
-    fread(&sscale,sizeof(double),1,fp);
-    fread(&dscale,sizeof(double),1,fp);
-    fread(&offset_flag,sizeof(int),1,fp);
-    fread(&mix_flag,sizeof(int),1,fp);
-  }
-  MPI_Bcast(&cut_global,1,MPI_DOUBLE,0,world);
-  MPI_Bcast(&sscale,1,MPI_DOUBLE,0,world);
-  MPI_Bcast(&dscale,1,MPI_DOUBLE,0,world);
-  MPI_Bcast(&offset_flag,1,MPI_INT,0,world);
-  MPI_Bcast(&mix_flag,1,MPI_INT,0,world);
-}
-
-/* ---------------------------------------------------------------------- */
-
-double PairZhou::single(int i, int j, int itype, int jtype, double rsq,
-			 double factor_coul, double factor_lj,
-			 double &fforce)
-{
-  double r,dr,dexp,phi,r2inv,r6inv,ddexp,invexp;
-
-  r2inv = 1.0/rsq;
-  r6inv = r2inv*r2inv*r2inv;
-  r = sqrt(rsq);
-  dr = r - r0[itype][jtype];
-  dexp = exp(-alpha[itype][jtype] * dr);
-  ddexp = exp(-dscale * (r/rr[itype][jtype] - 1.0));
-  invexp = 1.0/(1+ddexp);
-  fforce = factor_lj * morse1[itype][jtype] * (dexp*dexp - dexp) / r;
-  fforce -= factor_lj * sscale* c[itype][jtype] * (invexp*invexp*ddexp*(-dscale/rr[itype][jtype])*r6inv) / r;
-  fforce -= factor_lj * sscale* c[itype][jtype] * (6.0 * invexp * r6inv * r2inv);
-
-  phi = d0[itype][jtype] * (dexp*dexp - 2.0*dexp) - sscale*c[itype][jtype]*r6inv*invexp - offset[itype][jtype];
-  return factor_lj*phi;
-}
-
diff --git a/src/pair_zhou.h b/src/pair_zhou.h
deleted file mode 100644
index e8a4effa78..0000000000
--- a/src/pair_zhou.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/* ----------------------------------------------------------------------
-   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 PAIR_CLASS
-
-PairStyle(zhou,PairZhou)
-
-#else
-
-#ifndef LMP_PAIR_ZHOU_H
-#define LMP_PAIR_ZHOU_H
-
-#include "pair.h"
-
-namespace LAMMPS_NS {
-
-class PairZhou : public Pair {
- public:
-  PairZhou(class LAMMPS *);
-  virtual ~PairZhou();
-
-  virtual void compute(int, int);
-  virtual void settings(int, char **);
-  void coeff(int, char **);
-  virtual double init_one(int, int);
-  void write_restart(FILE *);
-  void read_restart(FILE *);
-  void write_restart_settings(FILE *);
-  void read_restart_settings(FILE *);
-  virtual double single(int, int, int, int, double, double, double, double &);
-
- protected:
-  double cut_global;
-  double **cut;
-  double sscale,dscale;
-  double **d0,**alpha,**r0,**c,**rr;
-  double **morse1;
-  double **offset;
-
-  void allocate();
-};
-
-}
-
-#endif
-#endif
-
-/* ERROR/WARNING messages:
-
-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: Incorrect args for pair coefficients
-
-Self-explanatory.  Check the input script or data file.
-
-E: All pair coeffs are not set
-
-All pair coefficients must be set in the data file or by the
-pair_coeff command before running a simulation.
-
-*/