git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@13643 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/atom.cpp

@@ -516,7 +516,7 @@ void Atom::modify_params(int narg, char **arg)
         error->all(FLERR,
                    "Atom_modify id command after simulation box is defined");
       if (strcmp(arg[iarg+1],"yes") == 0) tag_enable = 1;
-      else if (strcmp(arg[iarg+1],"no") == 0) tag_enable = 2;
+      else if (strcmp(arg[iarg+1],"no") == 0) tag_enable = 0;
       else error->all(FLERR,"Illegal atom_modify command");
       iarg += 2;
     } else if (strcmp(arg[iarg],"map") == 0) {
@@ -559,9 +559,11 @@ void Atom::modify_params(int narg, char **arg)
    check that atom IDs are valid
    error if any atom ID < 0 or atom ID = MAXTAGINT
    if any atom ID > 0, error if any atom ID == 0
+   if any atom ID > 0, error if tag_enable = 0
    if all atom IDs = 0, tag_enable must be 0
-   OK if atom IDs > natoms
+   if max atom IDs < natoms, must be duplicates
-   NOTE: not checking that atom IDs are unique
+   OK if max atom IDs > natoms
+   NOTE: not fully checking that atom IDs are unique
 ------------------------------------------------------------------------- */
 
 void Atom::tag_check()
@@ -578,12 +580,16 @@ void Atom::tag_check()
   MPI_Allreduce(&min,&minall,1,MPI_LMP_TAGINT,MPI_MIN,world);
   MPI_Allreduce(&max,&maxall,1,MPI_LMP_TAGINT,MPI_MAX,world);
 
-  if (minall < 0) error->all(FLERR,"Atom ID is negative");
+  if (minall < 0) error->all(FLERR,"One or more Atom IDs is negative");
-  if (maxall >= MAXTAGINT) error->all(FLERR,"Atom ID is too big");
+  if (maxall >= MAXTAGINT) error->all(FLERR,"One or more atom IDs is too big");
-  if (maxall > 0 && minall == 0) error->all(FLERR,"Atom ID is zero");
+  if (maxall > 0 && minall == 0) 
-  // this last message is wrong
+    error->all(FLERR,"One or more atom IDs is zero");
-  if (maxall == 0 && tag_enable && natoms) 
+  if (maxall > 0 && tag_enable == 0)
-    error->all(FLERR,"Not all atom IDs are 0");
+    error->all(FLERR,"Non-zero atom IDs with atom_modify id = no");
+  if (maxall == 0 && natoms && tag_enable) 
+    error->all(FLERR,"All atom IDs = 0 but atom_modify id = yes");
+  if (tag_enable && maxall < natoms)
+    error->all(FLERR,"Duplicate atom IDs exist");
 }
 
 /* ----------------------------------------------------------------------
@@ -725,7 +731,8 @@ void Atom::deallocate_topology()
    call style-specific routine to parse line
 ------------------------------------------------------------------------- */
 
-void Atom::data_atoms(int n, char *buf)
+void Atom::data_atoms(int n, char *buf, tagint id_offset, int type_offset, 
+                      int shiftflag, double *shift)
 {
   int m,xptr,iptr;
   imageint imagedata;
@@ -833,6 +840,12 @@ void Atom::data_atoms(int n, char *buf)
     xdata[0] = atof(values[xptr]);
     xdata[1] = atof(values[xptr+1]);
     xdata[2] = atof(values[xptr+2]);
+    if (shiftflag) {
+      xdata[0] += shift[0];
+      xdata[1] += shift[1];
+      xdata[2] += shift[2];
+    }
+
     domain->remap(xdata,imagedata);
     if (triclinic) {
       domain->x2lamda(xdata,lamda);
@@ -841,8 +854,15 @@ void Atom::data_atoms(int n, char *buf)
 
     if (coord[0] >= sublo[0] && coord[0] < subhi[0] &&
         coord[1] >= sublo[1] && coord[1] < subhi[1] &&
-        coord[2] >= sublo[2] && coord[2] < subhi[2])
+        coord[2] >= sublo[2] && coord[2] < subhi[2]) {
       avec->data_atom(xdata,imagedata,values);
+      if (id_offset) tag[nlocal-1] += id_offset;
+      if (type_offset) {
+        type[nlocal-1] += type_offset;
+        if (type[nlocal-1] > ntypes)
+          error->one(FLERR,"Invalid atom type in Atoms section of data file");
+      }
+    }
 
     buf = next + 1;
   }
@@ -856,7 +876,7 @@ void Atom::data_atoms(int n, char *buf)
    call style-specific routine to parse line
 ------------------------------------------------------------------------- */
 
-void Atom::data_vels(int n, char *buf)
+void Atom::data_vels(int n, char *buf, tagint id_offset)
 {
   int j,m;
   tagint tagdata;
@@ -883,7 +903,7 @@ void Atom::data_vels(int n, char *buf)
     for (j = 1; j < nwords; j++)
       values[j] = strtok(NULL," \t\n\r\f");
 
-    tagdata = ATOTAGINT(values[0]);
+    tagdata = ATOTAGINT(values[0]) + id_offset;
     if (tagdata <= 0 || tagdata > map_tag_max)
       error->one(FLERR,"Invalid atom ID in Velocities section of data file");
     if ((m = map(tagdata)) >= 0) avec->data_vel(m,&values[1]);
@@ -901,7 +921,7 @@ void Atom::data_vels(int n, char *buf)
    check that atom IDs are > 0 and <= map_tag_max
 ------------------------------------------------------------------------- */
 
-void Atom::data_bonds(int n, char *buf, int *count)
+void Atom::data_bonds(int n, char *buf, int *count, tagint id_offset)
 {
   int m,tmp,itype;
   tagint atom1,atom2;
@@ -913,6 +933,11 @@ void Atom::data_bonds(int n, char *buf, int *count)
     *next = '\0';
     sscanf(buf,"%d %d " TAGINT_FORMAT " " TAGINT_FORMAT,
            &tmp,&itype,&atom1,&atom2);
+    if (id_offset) {
+      atom1 += id_offset;
+      atom2 += id_offset;
+    }
+
     if (atom1 <= 0 || atom1 > map_tag_max ||
         atom2 <= 0 || atom2 > map_tag_max)
       error->one(FLERR,"Invalid atom ID in Bonds section of data file");
@@ -947,7 +972,7 @@ void Atom::data_bonds(int n, char *buf, int *count)
    check that atom IDs are > 0 and <= map_tag_max
 ------------------------------------------------------------------------- */
 
-void Atom::data_angles(int n, char *buf, int *count)
+void Atom::data_angles(int n, char *buf, int *count, tagint id_offset)
 {
   int m,tmp,itype;
   tagint atom1,atom2,atom3;
@@ -959,6 +984,12 @@ void Atom::data_angles(int n, char *buf, int *count)
     *next = '\0';
     sscanf(buf,"%d %d " TAGINT_FORMAT " " TAGINT_FORMAT " " TAGINT_FORMAT,
            &tmp,&itype,&atom1,&atom2,&atom3);
+    if (id_offset) {
+      atom1 += id_offset;
+      atom2 += id_offset;
+      atom3 += id_offset;
+    }
+
     if (atom1 <= 0 || atom1 > map_tag_max ||
         atom2 <= 0 || atom2 > map_tag_max ||
         atom3 <= 0 || atom3 > map_tag_max)
@@ -1008,7 +1039,7 @@ void Atom::data_angles(int n, char *buf, int *count)
    check that atom IDs are > 0 and <= map_tag_max
 ------------------------------------------------------------------------- */
 
-void Atom::data_dihedrals(int n, char *buf, int *count)
+void Atom::data_dihedrals(int n, char *buf, int *count, tagint id_offset)
 {
   int m,tmp,itype;
   tagint atom1,atom2,atom3,atom4;
@@ -1021,6 +1052,13 @@ void Atom::data_dihedrals(int n, char *buf, int *count)
     sscanf(buf,"%d %d " 
            TAGINT_FORMAT " " TAGINT_FORMAT " " TAGINT_FORMAT " " TAGINT_FORMAT,
            &tmp,&itype,&atom1,&atom2,&atom3,&atom4);
+    if (id_offset) {
+      atom1 += id_offset;
+      atom2 += id_offset;
+      atom3 += id_offset;
+      atom4 += id_offset;
+    }
+
     if (atom1 <= 0 || atom1 > map_tag_max ||
         atom2 <= 0 || atom2 > map_tag_max ||
         atom3 <= 0 || atom3 > map_tag_max ||
@@ -1086,7 +1124,7 @@ void Atom::data_dihedrals(int n, char *buf, int *count)
    check that atom IDs are > 0 and <= map_tag_max
 ------------------------------------------------------------------------- */
 
-void Atom::data_impropers(int n, char *buf, int *count)
+void Atom::data_impropers(int n, char *buf, int *count, tagint id_offset)
 {
   int m,tmp,itype;
   tagint atom1,atom2,atom3,atom4;
@@ -1099,6 +1137,13 @@ void Atom::data_impropers(int n, char *buf, int *count)
     sscanf(buf,"%d %d " 
            TAGINT_FORMAT " " TAGINT_FORMAT " " TAGINT_FORMAT " " TAGINT_FORMAT,
            &tmp,&itype,&atom1,&atom2,&atom3,&atom4);
+    if (id_offset) {
+      atom1 += id_offset;
+      atom2 += id_offset;
+      atom3 += id_offset;
+      atom4 += id_offset;
+    }
+
     if (atom1 <= 0 || atom1 > map_tag_max ||
         atom2 <= 0 || atom2 > map_tag_max ||
         atom3 <= 0 || atom3 > map_tag_max ||
@@ -1163,7 +1208,7 @@ void Atom::data_impropers(int n, char *buf, int *count)
    call style-specific routine to parse line
 ------------------------------------------------------------------------- */
 
-void Atom::data_bonus(int n, char *buf, AtomVec *avec_bonus)
+void Atom::data_bonus(int n, char *buf, AtomVec *avec_bonus, tagint id_offset)
 {
   int j,m,tagdata;
   char *next;
@@ -1189,7 +1234,7 @@ void Atom::data_bonus(int n, char *buf, AtomVec *avec_bonus)
     for (j = 1; j < nwords; j++)
       values[j] = strtok(NULL," \t\n\r\f");
 
-    tagdata = ATOTAGINT(values[0]);
+    tagdata = ATOTAGINT(values[0]) + id_offset;
     if (tagdata <= 0 || tagdata > map_tag_max)
       error->one(FLERR,"Invalid atom ID in Bonus section of data file");
 
@@ -1210,7 +1255,8 @@ void Atom::data_bonus(int n, char *buf, AtomVec *avec_bonus)
    call style-specific routine to parse line
 ------------------------------------------------------------------------- */
 
-void Atom::data_bodies(int n, char *buf, AtomVecBody *avec_body)
+void Atom::data_bodies(int n, char *buf, AtomVecBody *avec_body, 
+                       tagint id_offset)
 {
   int j,m,tagdata,ninteger,ndouble;
 
@@ -1222,8 +1268,8 @@ void Atom::data_bodies(int n, char *buf, AtomVecBody *avec_body)
   // if I own atom tag, unpack its values
 
   for (int i = 0; i < n; i++) {
-    if (i == 0) tagdata = ATOTAGINT(strtok(buf," \t\n\r\f"));
+    if (i == 0) tagdata = ATOTAGINT(strtok(buf," \t\n\r\f")) + id_offset;
-    else tagdata = ATOTAGINT(strtok(NULL," \t\n\r\f"));
+    else tagdata = ATOTAGINT(strtok(NULL," \t\n\r\f")) + id_offset;
     ninteger = atoi(strtok(NULL," \t\n\r\f"));
     ndouble = atoi(strtok(NULL," \t\n\r\f"));
 
@@ -1260,9 +1306,10 @@ void Atom::allocate_type_arrays()
 /* ----------------------------------------------------------------------
    set a mass and flag it as set
    called from reading of data file
+   type_offset may be used when reading multiple data files
 ------------------------------------------------------------------------- */
 
-void Atom::set_mass(const char *str)
+void Atom::set_mass(const char *str, int type_offset)
 {
   if (mass == NULL) error->all(FLERR,"Cannot set mass for this atom style");
 
@@ -1270,6 +1317,7 @@ void Atom::set_mass(const char *str)
   double mass_one;
   int n = sscanf(str,"%d %lg",&itype,&mass_one);
   if (n != 2) error->all(FLERR,"Invalid mass line in data file");
+  itype += type_offset;
 
   if (itype < 1 || itype > ntypes)
     error->all(FLERR,"Invalid type for mass set");

src/atom.h

@@ -188,19 +188,19 @@ class Atom : protected Pointers {
 
   void deallocate_topology();
 
-  void data_atoms(int, char *);
+  void data_atoms(int, char *, tagint, int, int, double *);
-  void data_vels(int, char *);
+  void data_vels(int, char *, tagint);
 
-  void data_bonds(int, char *, int *);
+  void data_bonds(int, char *, int *, tagint);
-  void data_angles(int, char *, int *);
+  void data_angles(int, char *, int *, tagint);
-  void data_dihedrals(int, char *, int *);
+  void data_dihedrals(int, char *, int *, tagint);
-  void data_impropers(int, char *, int *);
+  void data_impropers(int, char *, int *, tagint);
 
-  void data_bonus(int, char *, class AtomVec *);
+  void data_bonus(int, char *, class AtomVec *, tagint);
-  void data_bodies(int, char *, class AtomVecBody *);
+  void data_bodies(int, char *, class AtomVecBody *, tagint);
 
   virtual void allocate_type_arrays();
-  void set_mass(const char *);
+  void set_mass(const char *, int);
   void set_mass(int, double);
   void set_mass(int, char **);
   void set_mass(double *);

src/group.cpp

@@ -587,6 +587,26 @@ int Group::find(const char *name)
   return -1;
 }
 
+/* ----------------------------------------------------------------------
+   find group with name or create group if it doesn't exist
+   return group index
+------------------------------------------------------------------------- */
+
+int Group::find_or_create(const char *name)
+{
+  int igroup = find(name);
+  if (igroup >= 0) return igroup;
+
+  if (ngroup == MAX_GROUP) error->all(FLERR,"Too many groups");
+  igroup = find_unused();
+  int n = strlen(name) + 1;
+  names[igroup] = new char[n];
+  strcpy(names[igroup],name);
+  ngroup++;
+
+  return igroup;
+}
+
 /* ----------------------------------------------------------------------
    return index of first available group
    should never be called when group limit has been reached

src/group.h

@@ -33,6 +33,7 @@ class Group : protected Pointers {
   void assign(int, char **);         // assign atoms to a group
   void create(char *, int *);        // add flagged atoms to a group
   int find(const char *);            // lookup name in list of groups
+  int find_or_create(const char *);  // lookup name or create new group
   void write_restart(FILE *);
   void read_restart(FILE *);
 

src/read_data.cpp

@@ -29,6 +29,7 @@
 #include "atom_vec_tri.h"
 #include "force.h"
 #include "molecule.h"
+#include "group.h"
 #include "comm.h"
 #include "update.h"
 #include "modify.h"
@@ -41,6 +42,7 @@
 #include "dihedral.h"
 #include "improper.h"
 #include "special.h"
+#include "irregular.h"
 #include "error.h"
 #include "memory.h"
 
@@ -55,6 +57,8 @@ using namespace LAMMPS_NS;
                            // customize for new sections
 #define NSECTIONS 25       // change when add to header::section_keywords
 
+enum{NONE,APPEND,VALUE,MERGE};
+
 // pair style suffixes to ignore
 // when matching Pair Coeffs comment to currently-defined pair style
 
@@ -115,8 +119,16 @@ void ReadData::command(int narg, char **arg)
 
   // optional args
 
-  addflag = mergeflag = 0;
+  addflag = NONE;
-  offset[0] = offset[1] = offset[2] = 0.0;
+  id_offset = 0;
+  offsetflag = shiftflag = 0;
+  toffset = boffset = aoffset = doffset = ioffset = 0;
+  shift[0] = shift[1] = shift[2] = 0.0;
+  extra_atom_types = extra_bond_types = extra_angle_types = 
+    extra_dihedral_types = extra_improper_types = 0;
+
+  groupbit = 0;
+
   nfix = 0;
   fix_index = NULL;
   fix_header = NULL;
@@ -125,18 +137,81 @@ void ReadData::command(int narg, char **arg)
   int iarg = 1;
   while (iarg < narg) {
     if (strcmp(arg[iarg],"add") == 0) {
-      addflag = 1;
+      if (iarg+2 > narg) error->all(FLERR,"Illegal read_data command");
-      iarg++;
+      if (strcmp(arg[iarg+1],"append") == 0) addflag = APPEND;
-    } else if (strcmp(arg[iarg],"merge") == 0) {
+      else if (strcmp(arg[iarg+1],"merge") == 0) addflag = MERGE;
-      mergeflag = 1;
+      else {
-      iarg++;
+        addflag = VALUE;
+        bigint offset = force->bnumeric(FLERR,arg[iarg+1]);
+        if (offset > MAXTAGINT) 
+          error->all(FLERR,"Read data add offset is too big");
+        id_offset = offset;
+      }
+      iarg += 2;
     } else if (strcmp(arg[iarg],"offset") == 0) {
-      if (iarg+4 > narg)
+      if (iarg+6 > narg) error->all(FLERR,"Illegal read_data command");
+      offsetflag = 1;
+      toffset = force->inumeric(FLERR,arg[iarg+1]);
+      boffset = force->inumeric(FLERR,arg[iarg+2]);
+      aoffset = force->inumeric(FLERR,arg[iarg+3]);
+      doffset = force->inumeric(FLERR,arg[iarg+4]);
+      ioffset = force->inumeric(FLERR,arg[iarg+5]);
+      if (toffset < 0 || boffset < 0 || aoffset < 0 || 
+          doffset < 0 || ioffset < 0) 
         error->all(FLERR,"Illegal read_data command");
-      offset[0] = force->numeric(FLERR,arg[iarg+1]);
+      iarg += 6;
-      offset[1] = force->numeric(FLERR,arg[iarg+2]);
+    } else if (strcmp(arg[iarg],"shift") == 0) {
-      offset[2] = force->numeric(FLERR,arg[iarg+3]);
+      if (iarg+4 > narg) error->all(FLERR,"Illegal read_data command");
+      shiftflag = 1;
+      shift[0] = force->numeric(FLERR,arg[iarg+1]);
+      shift[1] = force->numeric(FLERR,arg[iarg+2]);
+      shift[2] = force->numeric(FLERR,arg[iarg+3]);
+      if (domain->dimension == 2 && shift[2] != 0.0)
+        error->all(FLERR,"Non-zero read_data shift z value for 2d simulation");
       iarg += 4;
+
+    } else if (strcmp(arg[iarg],"extra/atom/types") == 0) {
+      if (iarg+2 > narg) error->all(FLERR,"Illegal read_data command");
+      extra_atom_types = force->inumeric(FLERR,arg[iarg+1]);
+      if (extra_atom_types < 0) error->all(FLERR,"Illegal read_data command");
+      iarg += 2;
+    } else if (strcmp(arg[iarg],"extra/bond/types") == 0) {
+      if (iarg+2 > narg) error->all(FLERR,"Illegal read_data command");
+      if (!atom->avec->bonds_allow) 
+        error->all(FLERR,"No bonds allowed with this atom style");
+      extra_bond_types = force->inumeric(FLERR,arg[iarg+1]);
+      if (extra_bond_types < 0) error->all(FLERR,"Illegal read_data command");
+      iarg += 2;
+    } else if (strcmp(arg[iarg],"extra/angle/types") == 0) {
+      if (iarg+2 > narg) error->all(FLERR,"Illegal read_data command");
+      if (!atom->avec->angles_allow) 
+        error->all(FLERR,"No angles allowed with this atom style");
+      extra_angle_types = force->inumeric(FLERR,arg[iarg+1]);
+      if (extra_angle_types < 0) error->all(FLERR,"Illegal read_data command");
+      iarg += 2;
+    } else if (strcmp(arg[iarg],"extra/dihedral/types") == 0) {
+      if (iarg+2 > narg) error->all(FLERR,"Illegal read_data command");
+      if (!atom->avec->dihedrals_allow) 
+        error->all(FLERR,"No dihedrals allowed with this atom style");
+      extra_dihedral_types = force->inumeric(FLERR,arg[iarg+1]);
+      if (extra_dihedral_types < 0) 
+        error->all(FLERR,"Illegal read_data command");
+      iarg += 2;
+    } else if (strcmp(arg[iarg],"extra/improper/types") == 0) {
+      if (iarg+2 > narg) error->all(FLERR,"Illegal read_data command");
+      if (!atom->avec->impropers_allow) 
+        error->all(FLERR,"No impropers allowed with this atom style");
+      extra_improper_types = force->inumeric(FLERR,arg[iarg+1]);
+      if (extra_improper_types < 0) 
+        error->all(FLERR,"Illegal read_data command");
+      iarg += 2;
+
+    } else if (strcmp(arg[iarg],"group") == 0) {
+      if (iarg+2 > narg) error->all(FLERR,"Illegal read_data command");
+      int igroup = group->find_or_create(arg[iarg+1]);
+      groupbit = group->bitmask[igroup];
+      iarg += 2;
+
     } else if (strcmp(arg[iarg],"fix") == 0) {
       if (iarg+4 > narg)
         error->all(FLERR,"Illegal read_data command");
@@ -161,25 +236,54 @@ void ReadData::command(int narg, char **arg)
       strcpy(fix_section[nfix],arg[iarg+3]);
       nfix++;
       iarg += 4;
+
     } else error->all(FLERR,"Illegal read_data command");
   }
 
   // error checks
 
-  if (domain->box_exist && !addflag && !mergeflag)
-    error->all(FLERR,"Cannot read_data after simulation box is defined");
-  if (addflag && mergeflag) error->all(FLERR,"Cannot read_data add and merge");
-  if (domain->dimension == 2 && offset[2] != 0.0)
-    error->all(FLERR,"Cannot use non-zero z offset in read_data "
-               "for 2d simulation");
-
   if (domain->dimension == 2 && domain->zperiodic == 0)
     error->all(FLERR,"Cannot run 2d simulation with nonperiodic Z dimension");
+  if (domain->box_exist && !addflag)
+    error->all(FLERR,"Cannot read_data without add keyword "
+               "after simulation box is defined");
+  if (!domain->box_exist && addflag)
+    error->all(FLERR,"Cannot use read_data add before "
+               "simulation box is defined");
+  if (offsetflag && addflag == NONE)
+    error->all(FLERR,"Cannot use read_data offset without add flag");
+  if (shiftflag && addflag == NONE)
+    error->all(FLERR,"Cannot use read_data shift without add flag");
+  if (addflag != NONE && 
+      (extra_atom_types || extra_bond_types || extra_angle_types || 
+       extra_dihedral_types || extra_improper_types))
+    error->all(FLERR,"Cannot use read_data extra with add flag");
+
+  // first time system initialization
+
+  if (addflag == NONE) {
+    domain->box_exist = 1;
+    update->ntimestep = 0;
+  }
+
+  // compute atomID offset for addflag = MERGE
+
+  if (addflag == APPEND) {
+    tagint *tag = atom->tag;
+    int nlocal = atom->nlocal;
+    tagint max = 0;
+    for (int i = 0; i < nlocal; i++) max = MAX(max,tag[i]);
+    MPI_Allreduce(&max,&id_offset,1,MPI_LMP_TAGINT,MPI_MAX,world);
+  }
+
+  // -----------------------------------------------------------------
 
   // perform 1-pass read if no molecular topoogy in file
   // perform 2-pass read if molecular topology,
   //   first pass calculates max topology/atom
 
+  // flags for this data file
+
   int atomflag,topoflag;
   int bondflag,angleflag,dihedralflag,improperflag;
   int ellipsoidflag,lineflag,triflag,bodyflag;
@@ -188,6 +292,14 @@ void ReadData::command(int narg, char **arg)
   bondflag = angleflag = dihedralflag = improperflag = 0;
   ellipsoidflag = lineflag = triflag = bodyflag = 0;
 
+  // values in this data file
+
+  natoms = ntypes = 0;
+  nbonds = nangles = ndihedrals = nimpropers = 0;
+  nbondtypes = nangletypes = ndihedraltypes = nimpropertypes = 0;
+  triclinic = 0;
+
+  int nlocal_previous = atom->nlocal;
   int firstpass = 1;
 
   while (1) {
@@ -204,16 +316,12 @@ void ReadData::command(int narg, char **arg)
     header();
 
     // problem setup using info from header
-    // 1st pass only
+    // only done once, if firstpass and first data file
-
-    if (firstpass) {
-      domain->box_exist = 1;
-      update->ntimestep = 0;
-    
     // apply extra settings before grow(), even if no topology in file
     // deallocate() insures new settings are used for topology arrays
     // if per-atom topology is in file, another grow() is done below
 
+    if (firstpass && addflag == NONE) {
       atom->bond_per_atom = atom->extra_bond_per_atom;
       atom->angle_per_atom = atom->extra_angle_per_atom;
       atom->dihedral_per_atom = atom->extra_dihedral_per_atom;
@@ -227,6 +335,37 @@ void ReadData::command(int narg, char **arg)
       atom->deallocate_topology();
       atom->avec->grow(n);
 
+      domain->boxlo[0] = boxlo[0]; domain->boxhi[0] = boxhi[0];
+      domain->boxlo[1] = boxlo[1]; domain->boxhi[1] = boxhi[1];
+      domain->boxlo[2] = boxlo[2]; domain->boxhi[2] = boxhi[2];
+
+      if (triclinic) {
+        domain->xy = xy; domain->xz = xz; domain->yz = yz;
+      }
+
+      domain->print_box("  ");
+      domain->set_initial_box();
+      domain->set_global_box();
+      comm->set_proc_grid();
+      domain->set_local_box();
+    }
+
+    // change simulation box to be union of existing box and new box + shift
+    // only done if firstpass and not first data file
+
+    if (firstpass && addflag != NONE) {
+      domain->boxlo[0] = MIN(domain->boxlo[0],boxlo[0]+shift[0]);
+      domain->boxhi[0] = MAX(domain->boxhi[0],boxhi[0]+shift[0]);
+      domain->boxlo[1] = MIN(domain->boxlo[1],boxlo[1]+shift[1]);
+      domain->boxhi[1] = MAX(domain->boxhi[1],boxhi[1]+shift[1]);
+      domain->boxlo[2] = MIN(domain->boxlo[2],boxlo[2]+shift[2]);
+      domain->boxhi[2] = MAX(domain->boxhi[2],boxhi[2]+shift[2]);
+
+      // NOTE: not sure what to do about this:
+      //if (triclinic) {
+      //  domain->xy = xy; domain->xz = xz; domain->yz = yz;
+      // }
+
       domain->print_box("  ");
       domain->set_initial_box();
       domain->set_global_box();
@@ -261,34 +400,34 @@ void ReadData::command(int narg, char **arg)
             error->warning(FLERR,"Atom style in data file differs "
                            "from currently defined atom style");
           atoms();
-        } else skip_lines(atom->natoms);
+        } else skip_lines(natoms);
       } else if (strcmp(keyword,"Velocities") == 0) {
         if (atomflag == 0) 
           error->all(FLERR,"Must read Atoms before Velocities");
         if (firstpass) velocities();
-        else skip_lines(atom->natoms);
+        else skip_lines(natoms);
 
       } else if (strcmp(keyword,"Bonds") == 0) {
         topoflag = bondflag = 1;
-        if (atom->nbonds == 0)
+        if (nbonds == 0)
           error->all(FLERR,"Invalid data file section: Bonds");
         if (atomflag == 0) error->all(FLERR,"Must read Atoms before Bonds");
         bonds(firstpass);
       } else if (strcmp(keyword,"Angles") == 0) {
         topoflag = angleflag = 1;
-        if (atom->nangles == 0)
+        if (nangles == 0)
           error->all(FLERR,"Invalid data file section: Angles");
         if (atomflag == 0) error->all(FLERR,"Must read Atoms before Angles");
         angles(firstpass);
       } else if (strcmp(keyword,"Dihedrals") == 0) {
         topoflag = dihedralflag = 1;
-        if (atom->ndihedrals == 0)
+        if (ndihedrals == 0)
           error->all(FLERR,"Invalid data file section: Dihedrals");
         if (atomflag == 0) error->all(FLERR,"Must read Atoms before Dihedrals");
         dihedrals(firstpass);
       } else if (strcmp(keyword,"Impropers") == 0) {
         topoflag = improperflag = 1;
-        if (atom->nimpropers == 0)
+        if (nimpropers == 0)
           error->all(FLERR,"Invalid data file section: Impropers");
         if (atomflag == 0) error->all(FLERR,"Must read Atoms before Impropers");
         impropers(firstpass);
@@ -325,7 +464,7 @@ void ReadData::command(int narg, char **arg)
 
       } else if (strcmp(keyword,"Masses") == 0) {
         if (firstpass) mass();
-        else skip_lines(atom->ntypes);
+        else skip_lines(ntypes);
       } else if (strcmp(keyword,"Pair Coeffs") == 0) {
         if (force->pair == NULL)
           error->all(FLERR,"Must define pair_style before Pair Coeffs");
@@ -334,7 +473,7 @@ void ReadData::command(int narg, char **arg)
             error->warning(FLERR,"Pair style in data file differs "
                            "from currently defined pair style");
           paircoeffs();
-        } else skip_lines(atom->ntypes);
+        } else skip_lines(ntypes);
       } else if (strcmp(keyword,"PairIJ Coeffs") == 0) {
         if (force->pair == NULL)
           error->all(FLERR,"Must define pair_style before PairIJ Coeffs");
@@ -343,7 +482,7 @@ void ReadData::command(int narg, char **arg)
             error->warning(FLERR,"Pair style in data file differs "
                            "from currently defined pair style");
           pairIJcoeffs();
-        } else skip_lines(atom->ntypes*(atom->ntypes+1)/2);
+        } else skip_lines(ntypes*(ntypes+1)/2);
       } else if (strcmp(keyword,"Bond Coeffs") == 0) {
         if (atom->avec->bonds_allow == 0)
           error->all(FLERR,"Invalid data file section: Bond Coeffs");
@@ -354,7 +493,7 @@ void ReadData::command(int narg, char **arg)
             error->warning(FLERR,"Bond style in data file differs "
                            "from currently defined bond style");
           bondcoeffs();
-        } else skip_lines(atom->nbondtypes);
+        } else skip_lines(nbondtypes);
       } else if (strcmp(keyword,"Angle Coeffs") == 0) {
         if (atom->avec->angles_allow == 0)
           error->all(FLERR,"Invalid data file section: Angle Coeffs");
@@ -365,7 +504,7 @@ void ReadData::command(int narg, char **arg)
             error->warning(FLERR,"Angle style in data file differs "
                            "from currently defined angle style");
           anglecoeffs(0);
-        } else skip_lines(atom->nangletypes);
+        } else skip_lines(nangletypes);
       } else if (strcmp(keyword,"Dihedral Coeffs") == 0) {
         if (atom->avec->dihedrals_allow == 0)
           error->all(FLERR,"Invalid data file section: Dihedral Coeffs");
@@ -376,7 +515,7 @@ void ReadData::command(int narg, char **arg)
             error->warning(FLERR,"Dihedral style in data file differs "
                            "from currently defined dihedral style");
           dihedralcoeffs(0);
-        } else skip_lines(atom->ndihedraltypes);
+        } else skip_lines(ndihedraltypes);
       } else if (strcmp(keyword,"Improper Coeffs") == 0) {
         if (atom->avec->impropers_allow == 0)
           error->all(FLERR,"Invalid data file section: Improper Coeffs");
@@ -387,7 +526,7 @@ void ReadData::command(int narg, char **arg)
             error->warning(FLERR,"Improper style in data file differs "
                            "from currently defined improper style");
           impropercoeffs(0);
-        } else skip_lines(atom->nimpropertypes);
+        } else skip_lines(nimpropertypes);
 
       } else if (strcmp(keyword,"BondBond Coeffs") == 0) {
         if (atom->avec->angles_allow == 0)
@@ -395,14 +534,14 @@ void ReadData::command(int narg, char **arg)
         if (force->angle == NULL)
           error->all(FLERR,"Must define angle_style before BondBond Coeffs");
         if (firstpass) anglecoeffs(1);
-        else skip_lines(atom->nangletypes);
+        else skip_lines(nangletypes);
       } else if (strcmp(keyword,"BondAngle Coeffs") == 0) {
         if (atom->avec->angles_allow == 0)
           error->all(FLERR,"Invalid data file section: BondAngle Coeffs");
         if (force->angle == NULL)
           error->all(FLERR,"Must define angle_style before BondAngle Coeffs");
         if (firstpass) anglecoeffs(2);
-        else skip_lines(atom->nangletypes);
+        else skip_lines(nangletypes);
 
       } else if (strcmp(keyword,"MiddleBondTorsion Coeffs") == 0) {
         if (atom->avec->dihedrals_allow == 0)
@@ -413,7 +552,7 @@ void ReadData::command(int narg, char **arg)
                      "Must define dihedral_style before "
                      "MiddleBondTorsion Coeffs");
         if (firstpass) dihedralcoeffs(1);
-        else skip_lines(atom->ndihedraltypes);
+        else skip_lines(ndihedraltypes);
       } else if (strcmp(keyword,"EndBondTorsion Coeffs") == 0) {
         if (atom->avec->dihedrals_allow == 0)
           error->all(FLERR,"Invalid data file section: EndBondTorsion Coeffs");
@@ -421,7 +560,7 @@ void ReadData::command(int narg, char **arg)
           error->all(FLERR,
                      "Must define dihedral_style before EndBondTorsion Coeffs");
         if (firstpass) dihedralcoeffs(2);
-        else skip_lines(atom->ndihedraltypes);
+        else skip_lines(ndihedraltypes);
       } else if (strcmp(keyword,"AngleTorsion Coeffs") == 0) {
         if (atom->avec->dihedrals_allow == 0)
           error->all(FLERR,"Invalid data file section: AngleTorsion Coeffs");
@@ -429,7 +568,7 @@ void ReadData::command(int narg, char **arg)
           error->all(FLERR,
                      "Must define dihedral_style before AngleTorsion Coeffs");
         if (firstpass) dihedralcoeffs(3);
-        else skip_lines(atom->ndihedraltypes);
+        else skip_lines(ndihedraltypes);
       } else if (strcmp(keyword,"AngleAngleTorsion Coeffs") == 0) {
         if (atom->avec->dihedrals_allow == 0)
           error->all(FLERR,
@@ -439,7 +578,7 @@ void ReadData::command(int narg, char **arg)
                      "Must define dihedral_style before "
                      "AngleAngleTorsion Coeffs");
         if (firstpass) dihedralcoeffs(4);
-        else skip_lines(atom->ndihedraltypes);
+        else skip_lines(ndihedraltypes);
       } else if (strcmp(keyword,"BondBond13 Coeffs") == 0) {
         if (atom->avec->dihedrals_allow == 0)
           error->all(FLERR,"Invalid data file section: BondBond13 Coeffs");
@@ -447,7 +586,7 @@ void ReadData::command(int narg, char **arg)
           error->all(FLERR,
                      "Must define dihedral_style before BondBond13 Coeffs");
         if (firstpass) dihedralcoeffs(5);
-        else skip_lines(atom->ndihedraltypes);
+        else skip_lines(ndihedraltypes);
         
       } else if (strcmp(keyword,"AngleAngle Coeffs") == 0) {
         if (atom->avec->impropers_allow == 0)
@@ -456,7 +595,7 @@ void ReadData::command(int narg, char **arg)
           error->all(FLERR,
                      "Must define improper_style before AngleAngle Coeffs");
         if (firstpass) impropercoeffs(1);
-        else skip_lines(atom->nimpropertypes);
+        else skip_lines(nimpropertypes);
 
       } else {
         char str[128];
@@ -469,7 +608,7 @@ void ReadData::command(int narg, char **arg)
 
     // error if natoms > 0 yet no atoms were read
 
-    if (atom->natoms > 0 && atomflag == 0)
+    if (natoms > 0 && atomflag == 0)
       error->all(FLERR,"No atoms in data file");
     
     // close file
@@ -486,9 +625,8 @@ void ReadData::command(int narg, char **arg)
     // at end of 1st pass, error check for required sections
     // customize for new sections
 
-    if ((atom->nbonds && !bondflag) || (atom->nangles && !angleflag) ||
+    if ((nbonds && !bondflag) || (nangles && !angleflag) ||
-        (atom->ndihedrals && !dihedralflag) ||
+        (ndihedrals && !dihedralflag) || (nimpropers && !improperflag))
-        (atom->nimpropers && !improperflag))
       error->one(FLERR,"Needed molecular topology not in data file");
 
     if ((nellipsoids && !ellipsoidflag) || (nlines && !lineflag) ||
@@ -510,6 +648,15 @@ void ReadData::command(int narg, char **arg)
     atom->avec->grow(atom->nmax);
   }
 
+  // assign atoms added by this data file to specified group
+
+  if (groupbit) {
+    int *mask = atom->mask;
+    int nlocal = atom->nlocal;
+    for (int i = nlocal_previous; i < nlocal; i++)
+      mask[i] |= groupbit;
+  }
+
   // create special bond lists for molecular systems
 
   if (atom->molecular == 1) {
@@ -590,6 +737,19 @@ void ReadData::command(int narg, char **arg)
 
   if (atom->molecular == 2) atom->avec->onemols[0]->check_attributes(1);
 
+  // if adding atoms, migrate atoms to new processors
+  // use irregular() b/c box size could have changed dramaticaly
+  // resulting in procs now owning very different subboxes
+  // with their previously owned atoms now far outside the subbox
+
+  if (addflag != NONE) {
+    if (domain->triclinic) domain->x2lamda(atom->nlocal);
+    Irregular *irregular = new Irregular(lmp);
+    irregular->migrate_atoms(1);
+    delete irregular;
+    if (domain->triclinic) domain->lamda2x(atom->nlocal);
+  }
+
   // shrink-wrap the box if necessary and move atoms to new procs
   // if atoms are lost is b/c data file box was far from shrink-wrapped
   // do not use irregular() comm, which would not lose atoms,
@@ -621,6 +781,7 @@ void ReadData::command(int narg, char **arg)
    header ends with EOF or non-blank line containing no header keyword
      if EOF, line is set to blank line
      else line has first keyword line for rest of file
+   some logic differs if adding atoms
 ------------------------------------------------------------------------- */
 
 void ReadData::header()
@@ -648,7 +809,7 @@ void ReadData::header()
 
   while (1) {
 
-    // read a line and bcast length if flag is set
+    // read a line and bcast length
 
     if (me == 0) {
       if (fgets(line,MAXLINE,fp) == NULL) n = 0;
@@ -689,7 +850,9 @@ void ReadData::header()
     // customize for new header lines
 
     if (strstr(line,"atoms")) {
-      sscanf(line,BIGINT_FORMAT,&atom->natoms);
+      sscanf(line,BIGINT_FORMAT,&natoms);
+      if (addflag == NONE) atom->natoms = natoms;
+      else atom->natoms += natoms;
 
     // check for these first
     // otherwise "triangles" will be matched as "angles"
@@ -710,43 +873,70 @@ void ReadData::header()
       if (!avec_body)
         error->all(FLERR,"No bodies allowed with this atom style");
       sscanf(line,BIGINT_FORMAT,&nbodies);
-    }
 
-    else if (strstr(line,"bonds")) sscanf(line,BIGINT_FORMAT,&atom->nbonds);
+    } else if (strstr(line,"bonds")) {
-    else if (strstr(line,"angles")) sscanf(line,BIGINT_FORMAT,&atom->nangles);
+      sscanf(line,BIGINT_FORMAT,&nbonds);
-    else if (strstr(line,"dihedrals")) sscanf(line,BIGINT_FORMAT,
+      if (addflag == NONE) atom->nbonds = nbonds;
-                                              &atom->ndihedrals);
+      else atom->nbonds += nbonds;
-    else if (strstr(line,"impropers")) sscanf(line,BIGINT_FORMAT,
+    } else if (strstr(line,"angles")) {
-                                              &atom->nimpropers);
+      sscanf(line,BIGINT_FORMAT,&nangles);
+      if (addflag == NONE) atom->nangles = nangles;
+      else atom->nangles += nangles;
+    } else if (strstr(line,"dihedrals")) {
+      sscanf(line,BIGINT_FORMAT,&ndihedrals);
+      if (addflag == NONE) atom->ndihedrals = ndihedrals;
+      else atom->ndihedrals += natoms;
+    } else if (strstr(line,"impropers")) {
+      sscanf(line,BIGINT_FORMAT,&nimpropers);
+      if (addflag == NONE) atom->nimpropers = nimpropers;
+      else atom->nimpropers += nimpropers;
       
-    else if (strstr(line,"atom types")) sscanf(line,"%d",&atom->ntypes);
+    // Atom class type settings are only set by first data file
-    else if (strstr(line,"bond types")) sscanf(line,"%d",&atom->nbondtypes);
-    else if (strstr(line,"angle types")) sscanf(line,"%d",&atom->nangletypes);
-    else if (strstr(line,"dihedral types"))
-      sscanf(line,"%d",&atom->ndihedraltypes);
-    else if (strstr(line,"improper types"))
-      sscanf(line,"%d",&atom->nimpropertypes);
 
-    else if (strstr(line,"extra bond per atom"))
+    } else if (strstr(line,"atom types")) {
-      sscanf(line,"%d",&atom->extra_bond_per_atom);
+      sscanf(line,"%d",&ntypes);
-    else if (strstr(line,"extra angle per atom"))
+      if (addflag == NONE) atom->ntypes = ntypes + extra_atom_types;
-      sscanf(line,"%d",&atom->extra_angle_per_atom);
+    } else if (strstr(line,"bond types")) {
-    else if (strstr(line,"extra dihedral per atom"))
+      sscanf(line,"%d",&nbondtypes);
-      sscanf(line,"%d",&atom->extra_dihedral_per_atom);
+      if (addflag == NONE) atom->nbondtypes = nbondtypes + extra_bond_types;
-    else if (strstr(line,"extra improper per atom"))
+    } else if (strstr(line,"angle types")) {
-      sscanf(line,"%d",&atom->extra_improper_per_atom);
+      sscanf(line,"%d",&nangletypes);
-    else if (strstr(line,"extra special per atom"))
+      if (addflag == NONE) atom->nangletypes = nangletypes + extra_angle_types;
-      sscanf(line,"%d",&force->special_extra);
+    } else if (strstr(line,"dihedral types")) {
+      sscanf(line,"%d",&ndihedraltypes);
+      if (addflag == NONE) 
+        atom->ndihedraltypes = ndihedraltypes + extra_dihedral_types;
+    } else if (strstr(line,"improper types")) {
+      sscanf(line,"%d",&nimpropertypes);
+      if (addflag == NONE) 
+        atom->nimpropertypes = nimpropertypes + extra_improper_types;
+
+    // these settings only used by first data file
+
+    } else if (strstr(line,"extra bond per atom")) {
+      if (addflag == NONE) sscanf(line,"%d",&atom->extra_bond_per_atom);
+    } else if (strstr(line,"extra angle per atom")) {
+      if (addflag == NONE) sscanf(line,"%d",&atom->extra_angle_per_atom);
+    } else if (strstr(line,"extra dihedral per atom")) {
+      if (addflag == NONE) sscanf(line,"%d",&atom->extra_dihedral_per_atom);
+    } else if (strstr(line,"extra improper per atom")) {
+      if (addflag == NONE) sscanf(line,"%d",&atom->extra_improper_per_atom);
+    } else if (strstr(line,"extra special per atom")) {
+      if (addflag == NONE) sscanf(line,"%d",&force->special_extra);
+
+    // local copy of box info
+    // so can treat differently for first vs subsequent data files
+
+    } else if (strstr(line,"xlo xhi")) {
+      sscanf(line,"%lg %lg",&boxlo[0],&boxhi[0]);
+    } else if (strstr(line,"ylo yhi")) {
+      sscanf(line,"%lg %lg",&boxlo[1],&boxhi[1]);
+    } else if (strstr(line,"zlo zhi")) {
+      sscanf(line,"%lg %lg",&boxlo[2],&boxhi[2]);
+    } else if (strstr(line,"xy xz yz")) {
+      triclinic = 1;
+      sscanf(line,"%lg %lg %lg",&xy,&xz,&yz);
 
-    else if (strstr(line,"xlo xhi"))
-      sscanf(line,"%lg %lg",&domain->boxlo[0],&domain->boxhi[0]);
-    else if (strstr(line,"ylo yhi"))
-      sscanf(line,"%lg %lg",&domain->boxlo[1],&domain->boxhi[1]);
-    else if (strstr(line,"zlo zhi"))
-      sscanf(line,"%lg %lg",&domain->boxlo[2],&domain->boxhi[2]);
-    else if (strstr(line,"xy xz yz")) {
-      domain->triclinic = 1;
-      sscanf(line,"%lg %lg %lg",&domain->xy,&domain->xz,&domain->yz);
     } else break;
   }
 
@@ -815,27 +1005,28 @@ void ReadData::atoms()
   }
 
   bigint nread = 0;
-  bigint natoms = atom->natoms;
 
   while (nread < natoms) {
     nchunk = MIN(natoms-nread,CHUNK);
     eof = comm->read_lines_from_file(fp,nchunk,MAXLINE,buffer);
     if (eof) error->all(FLERR,"Unexpected end of data file");
-    atom->data_atoms(nchunk,buffer);
+    atom->data_atoms(nchunk,buffer,id_offset,toffset,shiftflag,shift);
     nread += nchunk;
   }
 
   // check that all atoms were assigned correctly
 
-  bigint tmp = atom->nlocal;
+  bigint n = atom->nlocal;
-  MPI_Allreduce(&tmp,&natoms,1,MPI_LMP_BIGINT,MPI_SUM,world);
+  bigint sum;
+  MPI_Allreduce(&n,&sum,1,MPI_LMP_BIGINT,MPI_SUM,world);
+  bigint nassign = sum - (atom->natoms - natoms);
 
   if (me == 0) {
-    if (screen) fprintf(screen,"  " BIGINT_FORMAT " atoms\n",natoms);
+    if (screen) fprintf(screen,"  " BIGINT_FORMAT " atoms\n",nassign);
-    if (logfile) fprintf(logfile,"  " BIGINT_FORMAT " atoms\n",natoms);
+    if (logfile) fprintf(logfile,"  " BIGINT_FORMAT " atoms\n",nassign);
   }
 
-  if (natoms != atom->natoms)
+  if (sum != atom->natoms)
     error->all(FLERR,"Did not assign all atoms correctly");
   
   // check that atom IDs are valid
@@ -872,13 +1063,12 @@ void ReadData::velocities()
   }
 
   bigint nread = 0;
-  bigint natoms = atom->natoms;
 
   while (nread < natoms) {
     nchunk = MIN(natoms-nread,CHUNK);
     eof = comm->read_lines_from_file(fp,nchunk,MAXLINE,buffer);
     if (eof) error->all(FLERR,"Unexpected end of data file");
-    atom->data_vels(nchunk,buffer);
+    atom->data_vels(nchunk,buffer,id_offset);
     nread += nchunk;
   }
 
@@ -928,7 +1118,7 @@ void ReadData::bonds(int firstpass)
     nchunk = MIN(nbonds-nread,CHUNK);
     eof = comm->read_lines_from_file(fp,nchunk,MAXLINE,buffer);
     if (eof) error->all(FLERR,"Unexpected end of data file");
-    atom->data_bonds(nchunk,buffer,count);
+    atom->data_bonds(nchunk,buffer,count,id_offset);
     nread += nchunk;
   }
 
@@ -1003,7 +1193,7 @@ void ReadData::angles(int firstpass)
     nchunk = MIN(nangles-nread,CHUNK);
     eof = comm->read_lines_from_file(fp,nchunk,MAXLINE,buffer);
     if (eof) error->all(FLERR,"Unexpected end of data file");
-    atom->data_angles(nchunk,buffer,count);
+    atom->data_angles(nchunk,buffer,count,id_offset);
     nread += nchunk;
   }
 
@@ -1078,7 +1268,7 @@ void ReadData::dihedrals(int firstpass)
     nchunk = MIN(ndihedrals-nread,CHUNK);
     eof = comm->read_lines_from_file(fp,nchunk,MAXLINE,buffer);
     if (eof) error->all(FLERR,"Unexpected end of data file");
-    atom->data_dihedrals(nchunk,buffer,count);
+    atom->data_dihedrals(nchunk,buffer,count,id_offset);
     nread += nchunk;
   }
 
@@ -1153,7 +1343,7 @@ void ReadData::impropers(int firstpass)
     nchunk = MIN(nimpropers-nread,CHUNK);
     eof = comm->read_lines_from_file(fp,nchunk,MAXLINE,buffer);
     if (eof) error->all(FLERR,"Unexpected end of data file");
-    atom->data_impropers(nchunk,buffer,count);
+    atom->data_impropers(nchunk,buffer,count,id_offset);
     nread += nchunk;
   }
 
@@ -1216,7 +1406,7 @@ void ReadData::bonus(bigint nbonus, AtomVec *ptr, const char *type)
     nchunk = MIN(natoms-nread,CHUNK);
     eof = comm->read_lines_from_file(fp,nchunk,MAXLINE,buffer);
     if (eof) error->all(FLERR,"Unexpected end of data file");
-    atom->data_bonus(nchunk,buffer,ptr);
+    atom->data_bonus(nchunk,buffer,ptr,id_offset);
     nread += nchunk;
   }
 
@@ -1296,7 +1486,7 @@ void ReadData::bodies(int firstpass)
     MPI_Bcast(&m,1,MPI_INT,0,world);
     MPI_Bcast(buffer,m,MPI_CHAR,0,world);
 
-    if (firstpass) atom->data_bodies(nchunk,buffer,avec_body);
+    if (firstpass) atom->data_bodies(nchunk,buffer,avec_body,id_offset);
     nread += nchunk;
   }
 
@@ -1316,16 +1506,16 @@ void ReadData::bodies(int firstpass)
 void ReadData::mass()
 {
   char *next;
-  char *buf = new char[atom->ntypes*MAXLINE];
+  char *buf = new char[ntypes*MAXLINE];
 
-  int eof = comm->read_lines_from_file(fp,atom->ntypes,MAXLINE,buf);
+  int eof = comm->read_lines_from_file(fp,ntypes,MAXLINE,buf);
   if (eof) error->all(FLERR,"Unexpected end of data file");
 
   char *original = buf;
-  for (int i = 0; i < atom->ntypes; i++) {
+  for (int i = 0; i < ntypes; i++) {
     next = strchr(buf,'\n');
     *next = '\0';
-    atom->set_mass(buf);
+    atom->set_mass(buf,toffset);
     buf = next + 1;
   }
   delete [] original;
@@ -1336,16 +1526,16 @@ void ReadData::mass()
 void ReadData::paircoeffs()
 {
   char *next;
-  char *buf = new char[atom->ntypes*MAXLINE];
+  char *buf = new char[ntypes*MAXLINE];
 
-  int eof = comm->read_lines_from_file(fp,atom->ntypes,MAXLINE,buf);
+  int eof = comm->read_lines_from_file(fp,ntypes,MAXLINE,buf);
   if (eof) error->all(FLERR,"Unexpected end of data file");
 
   char *original = buf;
-  for (int i = 0; i < atom->ntypes; i++) {
+  for (int i = 0; i < ntypes; i++) {
     next = strchr(buf,'\n');
     *next = '\0';
-    parse_coeffs(buf,NULL,1);
+    parse_coeffs(buf,NULL,1,2,toffset);
     if (narg == 0) error->all(FLERR,"Unexpected end of PairCoeffs section");
     force->pair->coeff(narg,arg);
     buf = next + 1;
@@ -1360,18 +1550,18 @@ void ReadData::pairIJcoeffs()
   int i,j;
   char *next;
   
-  int nsq = atom->ntypes* (atom->ntypes+1) / 2;
+  int nsq = ntypes * (ntypes+1) / 2;
   char *buf = new char[nsq * MAXLINE];
 
   int eof = comm->read_lines_from_file(fp,nsq,MAXLINE,buf);
   if (eof) error->all(FLERR,"Unexpected end of data file");
 
   char *original = buf;
-  for (i = 0; i < atom->ntypes; i++)
+  for (i = 0; i < ntypes; i++)
-    for (j = i; j < atom->ntypes; j++) {
+    for (j = i; j < ntypes; j++) {
       next = strchr(buf,'\n');
       *next = '\0';
-      parse_coeffs(buf,NULL,0);
+      parse_coeffs(buf,NULL,0,2,toffset);
       if (narg == 0) error->all(FLERR,"Unexpected end of PairCoeffs section");
       force->pair->coeff(narg,arg);
       buf = next + 1;
@@ -1384,16 +1574,16 @@ void ReadData::pairIJcoeffs()
 void ReadData::bondcoeffs()
 {
   char *next;
-  char *buf = new char[atom->nbondtypes*MAXLINE];
+  char *buf = new char[nbondtypes*MAXLINE];
 
-  int eof = comm->read_lines_from_file(fp,atom->nbondtypes,MAXLINE,buf);
+  int eof = comm->read_lines_from_file(fp,nbondtypes,MAXLINE,buf);
   if (eof) error->all(FLERR,"Unexpected end of data file");
 
   char *original = buf;
-  for (int i = 0; i < atom->nbondtypes; i++) {
+  for (int i = 0; i < nbondtypes; i++) {
     next = strchr(buf,'\n');
     *next = '\0';
-    parse_coeffs(buf,NULL,0);
+    parse_coeffs(buf,NULL,0,1,boffset);
     if (narg == 0) error->all(FLERR,"Unexpected end of BondCoeffs section");
     force->bond->coeff(narg,arg);
     buf = next + 1;
@@ -1406,18 +1596,18 @@ void ReadData::bondcoeffs()
 void ReadData::anglecoeffs(int which)
 {
   char *next;
-  char *buf = new char[atom->nangletypes*MAXLINE];
+  char *buf = new char[nangletypes*MAXLINE];
 
-  int eof = comm->read_lines_from_file(fp,atom->nangletypes,MAXLINE,buf);
+  int eof = comm->read_lines_from_file(fp,nangletypes,MAXLINE,buf);
   if (eof) error->all(FLERR,"Unexpected end of data file");
 
   char *original = buf;
-  for (int i = 0; i < atom->nangletypes; i++) {
+  for (int i = 0; i < nangletypes; i++) {
     next = strchr(buf,'\n');
     *next = '\0';
-    if (which == 0) parse_coeffs(buf,NULL,0);
+    if (which == 0) parse_coeffs(buf,NULL,0,1,aoffset);
-    else if (which == 1) parse_coeffs(buf,"bb",0);
+    else if (which == 1) parse_coeffs(buf,"bb",0,1,aoffset);
-    else if (which == 2) parse_coeffs(buf,"ba",0);
+    else if (which == 2) parse_coeffs(buf,"ba",0,1,aoffset);
     if (narg == 0) error->all(FLERR,"Unexpected end of AngleCoeffs section");
     force->angle->coeff(narg,arg);
     buf = next + 1;
@@ -1430,21 +1620,21 @@ void ReadData::anglecoeffs(int which)
 void ReadData::dihedralcoeffs(int which)
 {
   char *next;
-  char *buf = new char[atom->ndihedraltypes*MAXLINE];
+  char *buf = new char[ndihedraltypes*MAXLINE];
 
-  int eof = comm->read_lines_from_file(fp,atom->ndihedraltypes,MAXLINE,buf);
+  int eof = comm->read_lines_from_file(fp,ndihedraltypes,MAXLINE,buf);
   if (eof) error->all(FLERR,"Unexpected end of data file");
 
   char *original = buf;
-  for (int i = 0; i < atom->ndihedraltypes; i++) {
+  for (int i = 0; i < ndihedraltypes; i++) {
     next = strchr(buf,'\n');
     *next = '\0';
-    if (which == 0) parse_coeffs(buf,NULL,0);
+    if (which == 0) parse_coeffs(buf,NULL,0,1,doffset);
-    else if (which == 1) parse_coeffs(buf,"mbt",0);
+    else if (which == 1) parse_coeffs(buf,"mbt",0,1,doffset);
-    else if (which == 2) parse_coeffs(buf,"ebt",0);
+    else if (which == 2) parse_coeffs(buf,"ebt",0,1,doffset);
-    else if (which == 3) parse_coeffs(buf,"at",0);
+    else if (which == 3) parse_coeffs(buf,"at",0,1,doffset);
-    else if (which == 4) parse_coeffs(buf,"aat",0);
+    else if (which == 4) parse_coeffs(buf,"aat",0,1,doffset);
-    else if (which == 5) parse_coeffs(buf,"bb13",0);
+    else if (which == 5) parse_coeffs(buf,"bb13",0,1,doffset);
     if (narg == 0) error->all(FLERR,"Unexpected end of DihedralCoeffs section");
     force->dihedral->coeff(narg,arg);
     buf = next + 1;
@@ -1457,17 +1647,17 @@ void ReadData::dihedralcoeffs(int which)
 void ReadData::impropercoeffs(int which)
 {
   char *next;
-  char *buf = new char[atom->nimpropertypes*MAXLINE];
+  char *buf = new char[nimpropertypes*MAXLINE];
 
-  int eof = comm->read_lines_from_file(fp,atom->nimpropertypes,MAXLINE,buf);
+  int eof = comm->read_lines_from_file(fp,nimpropertypes,MAXLINE,buf);
   if (eof) error->all(FLERR,"Unexpected end of data file");
 
   char *original = buf;
-  for (int i = 0; i < atom->nimpropertypes; i++) {
+  for (int i = 0; i < nimpropertypes; i++) {
     next = strchr(buf,'\n');
     *next = '\0';
-    if (which == 0) parse_coeffs(buf,NULL,0);
+    if (which == 0) parse_coeffs(buf,NULL,0,1,ioffset);
-    else if (which == 1) parse_coeffs(buf,"aa",0);
+    else if (which == 1) parse_coeffs(buf,"aa",0,1,ioffset);
     if (narg == 0) error->all(FLERR,"Unexpected end of ImproperCoeffs section");
     force->improper->coeff(narg,arg);
     buf = next + 1;
@@ -1634,9 +1824,11 @@ void ReadData::skip_lines(bigint n)
      if 2nd word starts with letter, then is hybrid style, add addstr after it
      else add addstr before 2nd word
    if dupflag, duplicate 1st word, so pair_coeff "2" becomes "2 2"
+   if noffset, add offset to first noffset args, which are atom/bond/etc types
 ------------------------------------------------------------------------- */
 
-void ReadData::parse_coeffs(char *line, const char *addstr, int dupflag)
+void ReadData::parse_coeffs(char *line, const char *addstr,
+                            int dupflag, int noffset, int offset)
 {
   char *ptr;
   if ((ptr = strchr(line,'#'))) *ptr = '\0';
@@ -1655,6 +1847,17 @@ void ReadData::parse_coeffs(char *line, const char *addstr, int dupflag)
     if (dupflag && narg == 1) arg[narg++] = word;
     word = strtok(NULL," \t\n\r\f");
   }
+
+  if (noffset) {
+    int value = force->inumeric(FLERR,arg[0]);
+    sprintf(argoffset1,"%d",value+offset);
+    arg[0] = argoffset1;
+    if (noffset == 2) {
+      value = force->inumeric(FLERR,arg[1]);
+      sprintf(argoffset2,"%d",value+offset);
+      arg[1] = argoffset2;
+    }
+  }
 }
 
 /* ----------------------------------------------------------------------

src/read_data.h

@@ -32,19 +32,19 @@ class ReadData : protected Pointers {
   void command(int, char **);
 
  private:
+  int me,compressed;
   char *line,*keyword,*buffer,*style;
   FILE *fp;
   char **arg;
-  int me,narg,maxarg,compressed;
+  int narg,maxarg;
+  char argoffset1[8],argoffset2[8];
 
-  // optional args
+  bigint id_offset;
 
-  int addflag,mergeflag;
+  bigint natoms;
-  double offset[3];
+  bigint nbonds,nangles,ndihedrals,nimpropers;
-  int nfix;         
+  int ntypes;
-  int *fix_index;
+  int nbondtypes,nangletypes,ndihedraltypes,nimpropertypes;
-  char **fix_header;
-  char **fix_section;
 
   bigint nellipsoids;
   class AtomVecEllipsoid *avec_ellipsoid;
@@ -55,13 +55,36 @@ class ReadData : protected Pointers {
   bigint nbodies;
   class AtomVecBody *avec_body;
 
+  // box info
+
+  double boxlo[3],boxhi[3];
+  double xy,xz,yz;
+  int triclinic;
+
+  // optional args
+
+  int addflag,offsetflag,shiftflag;
+  tagint addvalue;
+  int toffset,boffset,aoffset,doffset,ioffset;
+  double shift[3];
+  int extra_atom_types,extra_bond_types,extra_angle_types;
+  int extra_dihedral_types,extra_improper_types;
+  int groupbit;
+
+  int nfix;         
+  int *fix_index;
+  char **fix_header;
+  char **fix_section;
+
+  // methods
+
   void open(char *);
   void scan(int &, int &, int &, int &);
   int reallocate(int **, int, int);
   void header();
   void parse_keyword(int);
   void skip_lines(bigint);
-  void parse_coeffs(char *, const char *, int);
+  void parse_coeffs(char *, const char *, int, int, int);
   int style_match(const char *, const char *);
 
   void atoms();