diff --git a/src/USER-COLVARS/README b/src/USER-COLVARS/README
index bcccbe4a5a..06efa1f4b7 100644
--- a/src/USER-COLVARS/README
+++ b/src/USER-COLVARS/README
@@ -44,4 +44,4 @@ The person who created this package is Axel Kohlmeyer at Temple U
 
 ---------------------------------
 
-Version: 2013-06-27
+Version: 2013-12-16
diff --git a/src/USER-COLVARS/colvarproxy_lammps.cpp b/src/USER-COLVARS/colvarproxy_lammps.cpp
index 25575a34a5..3a65221462 100644
--- a/src/USER-COLVARS/colvarproxy_lammps.cpp
+++ b/src/USER-COLVARS/colvarproxy_lammps.cpp
@@ -1,7 +1,3 @@
-#ifdef LAMMPS_BIGBIG
-#error LAMMPS_BIGBIG not supported by this file
-#endif
-
 #include "mpi.h"
 #include "lammps.h"
 #include "atom.h"
diff --git a/src/USER-COLVARS/fix_colvars.cpp b/src/USER-COLVARS/fix_colvars.cpp
index 9f7304f447..5927d8f63e 100644
--- a/src/USER-COLVARS/fix_colvars.cpp
+++ b/src/USER-COLVARS/fix_colvars.cpp
@@ -443,6 +443,11 @@ void FixColvars::one_time_init()
     if (screen) fputs("colvars: Creating proxy instance\n",screen);
     if (logfile) fputs("colvars: Creating proxy instance\n",logfile);
 
+#ifdef LAMMPS_BIGBIG
+    if (screen) fputs("colvars: cannot handle atom ids > 2147483647\n",screen);
+    if (logfile) fputs("colvars: cannot handle atom ids > 2147483647\n",logfile);
+#endif
+
     if (inp_name) {
       if (strcmp(inp_name,"NULL") == 0) {
         memory->sfree(inp_name);
@@ -490,14 +495,14 @@ void FixColvars::one_time_init()
       inthash_insert(hashtable, tl[i], i);
     }
   }
-  MPI_Bcast(taglist, num_coords, MPI_INT, 0, world);
+  MPI_Bcast(taglist, num_coords, MPI_LMP_TAGINT, 0, world);
 }
 
 /* ---------------------------------------------------------------------- */
 
 void FixColvars::setup(int vflag)
 {
-  const int * const tag  = atom->tag;
+  const tagint * const tag  = atom->tag;
   const int * const type = atom->type;
   int i,nme,tmp,ndata;
   int nlocal = atom->nlocal;
@@ -510,7 +515,7 @@ void FixColvars::setup(int vflag)
   // determine size of comm buffer
   nme=0;
   for (i=0; i < num_coords; ++i) {
-    const int k = atom->map(taglist[i]);
+    const tagint k = atom->map(taglist[i]);
     if ((k >= 0) && (k < nlocal))
       ++nme;
   }
@@ -536,7 +541,7 @@ void FixColvars::setup(int vflag)
     // store coordinate data in holding array, clear old forces
 
     for (i=0; i<num_coords; ++i) {
-      const int k = atom->map(taglist[i]);
+      const tagint k = atom->map(taglist[i]);
       if ((k >= 0) && (k < nlocal)) {
 
         of[i].tag  = cd[i].tag  = tag[k];
@@ -593,7 +598,7 @@ void FixColvars::setup(int vflag)
 
     nme = 0;
     for (i=0; i<num_coords; ++i) {
-      const int k = atom->map(taglist[i]);
+      const tagint k = atom->map(taglist[i]);
       if ((k >= 0) && (k < nlocal)) {
 
         comm_buf[nme].tag  = tag[k];
@@ -665,7 +670,7 @@ void FixColvars::post_force(int vflag)
     }
   }
 
-  const int * const tag = atom->tag;
+  const tagint * const tag = atom->tag;
   const double * const * const x = atom->x;
   double * const * const f = atom->f;
   const imageint * const image = atom->image;
@@ -681,7 +686,7 @@ void FixColvars::post_force(int vflag)
   /* check and potentially grow local communication buffers. */
   int i,nmax_new,nme=0;
   for (i=0; i < num_coords; ++i) {
-    const int k = atom->map(taglist[i]);
+    const tagint k = atom->map(taglist[i]);
     if ((k >= 0) && (k < nlocal))
       ++nme;
   }
@@ -702,7 +707,7 @@ void FixColvars::post_force(int vflag)
     // store coordinate data
 
     for (i=0; i<num_coords; ++i) {
-      const int k = atom->map(taglist[i]);
+      const tagint k = atom->map(taglist[i]);
       if ((k >= 0) && (k < nlocal)) {
 
         if (unwrap_flag) {
@@ -744,7 +749,7 @@ void FixColvars::post_force(int vflag)
     /* copy coordinate data into communication buffer */
     nme = 0;
     for (i=0; i<num_coords; ++i) {
-      const int k = atom->map(taglist[i]);
+      const tagint k = atom->map(taglist[i]);
       if ((k >= 0) && (k < nlocal)) {
         comm_buf[nme].tag = tag[k];
 
@@ -796,7 +801,7 @@ void FixColvars::post_force(int vflag)
   MPI_Bcast(force_buf, 3*num_coords, MPI_DOUBLE, 0, world);
 
   for (int i=0; i < num_coords; ++i) {
-    const int k = atom->map(taglist[i]);
+    const tagint k = atom->map(taglist[i]);
     if ((k >= 0) && (k < nlocal)) {
       f[k][0] += force_buf[3*i+0];
       f[k][1] += force_buf[3*i+1];
@@ -824,14 +829,14 @@ void FixColvars::end_of_step()
 {
   if (store_forces) {
 
-    const int * const tag = atom->tag;
+    const tagint * const tag = atom->tag;
     double * const * const f = atom->f;
     const int nlocal = atom->nlocal;
 
     /* check and potentially grow local communication buffers. */
     int i,nmax_new,nme=0;
     for (i=0; i < num_coords; ++i) {
-      const int k = atom->map(taglist[i]);
+      const tagint k = atom->map(taglist[i]);
       if ((k >= 0) && (k < nlocal))
         ++nme;
     }
@@ -852,7 +857,7 @@ void FixColvars::end_of_step()
       std::vector<struct commdata> &of = *oforce;
 
       for (i=0; i<num_coords; ++i) {
-        const int k = atom->map(taglist[i]);
+        const tagint k = atom->map(taglist[i]);
         if ((k >= 0) && (k < nlocal)) {
 
           const int j = inthash_lookup(idmap, tag[k]);
@@ -887,7 +892,7 @@ void FixColvars::end_of_step()
       /* copy total force data into communication buffer */
       nme = 0;
       for (i=0; i<num_coords; ++i) {
-        const int k = atom->map(taglist[i]);
+        const tagint k = atom->map(taglist[i]);
         if ((k >= 0) && (k < nlocal)) {
           comm_buf[nme].tag  = tag[k];
           comm_buf[nme].x    = f[k][0];
diff --git a/src/USER-COLVARS/fix_colvars.h b/src/USER-COLVARS/fix_colvars.h
index d0b7f765c0..d62a909303 100644
--- a/src/USER-COLVARS/fix_colvars.h
+++ b/src/USER-COLVARS/fix_colvars.h
@@ -65,7 +65,7 @@ class FixColvars : public Fix {
 
   int   me;            // my MPI rank in this "world".
   int   num_coords;    // total number of atoms controlled by this fix
-  int   *taglist;      // list of all atom IDs referenced by colvars.
+  tagint *taglist;     // list of all atom IDs referenced by colvars.
   std::vector<struct commdata> *coords; // coordinates of colvar atoms
   std::vector<struct commdata> *forces; // received forces of colvar atoms
   std::vector<struct commdata> *oforce; // old total forces of colvar atoms
diff --git a/src/USER-COLVARS/group_ndx.cpp b/src/USER-COLVARS/group_ndx.cpp
index de63fc7d97..33a8b75993 100644
--- a/src/USER-COLVARS/group_ndx.cpp
+++ b/src/USER-COLVARS/group_ndx.cpp
@@ -30,10 +30,10 @@ using namespace LAMMPS_NS;
    helper function. integer comparison for qsort()
    ---------------------------------------------------------------------- */
 
-static int cmpint(const void *p1, const void *p2)
+static int cmptagint(const void *p1, const void *p2)
 {
-  const int i1 = * static_cast<const int *>(p1);
-  const int i2 = * static_cast<const int *>(p2);
+  const tagint i1 = * static_cast<const tagint *>(p1);
+  const tagint i2 = * static_cast<const tagint *>(p2);
   if (i1 == i2) return 0;
   else {
     if (i1 < i2) return -1;
@@ -49,7 +49,7 @@ static void write_group(FILE *fp, int gid, Atom *atom, Group *group, int me,
                         int np, MPI_Comm world, FILE *screen, FILE *logfile)
 {
   char fmt[8];
-  int *sendlist, *recvlist;
+  tagint *sendlist, *recvlist;
   bigint num = group->count(gid);
   int lnum, cols;
 
@@ -77,13 +77,13 @@ static void write_group(FILE *fp, int gid, Atom *atom, Group *group, int me,
 
   if (num > 0) {
     const int * const mask = atom->mask;
-    const int * const tag = atom->tag;
+    const tagint * const tag = atom->tag;
     const int groupbit = group->bitmask[gid];
     const int nlocal = atom->nlocal;
     int i,j;
 
-    sendlist = new int[nlocal];
-    recvlist = new int[num];
+    sendlist = new tagint[nlocal];
+    recvlist = new tagint[num];
     lnum = 0;
     for (i = 0; i < nlocal; i++)
       if (mask[i] & groupbit) sendlist[lnum++] = tag[i];
@@ -97,18 +97,18 @@ static void write_group(FILE *fp, int gid, Atom *atom, Group *group, int me,
 
       allrecv = lnum;
       for (int i=1; i < np; ++i) {
-        MPI_Irecv(recvlist+allrecv,num-allrecv,MPI_INT,i,0, world,&request);
+        MPI_Irecv(recvlist+allrecv,num-allrecv,MPI_LMP_TAGINT,i,0, world,&request);
         MPI_Send(&nrecv,0,MPI_INT,i,0,world);
         MPI_Wait(&request,&status);
-        MPI_Get_count(&status,MPI_INT,&nrecv);
+        MPI_Get_count(&status,MPI_LMP_TAGINT,&nrecv);
         allrecv += nrecv;
       }
 
       // sort received list
-      qsort((void *)recvlist, num, sizeof(int), cmpint);
+      qsort((void *)recvlist, num, sizeof(tagint), cmptagint);
     } else {
       MPI_Recv(&nrecv,0,MPI_INT,0,0,world,&status);
-      MPI_Rsend(sendlist,lnum,MPI_INT,0,0,world);
+      MPI_Rsend(sendlist,lnum,MPI_LMP_TAGINT,0,0,world);
     }
     delete [] sendlist;
   }
diff --git a/src/USER-MISC/fix_imd.cpp b/src/USER-MISC/fix_imd.cpp
index 9370c76c68..9827b92ed6 100644
--- a/src/USER-MISC/fix_imd.cpp
+++ b/src/USER-MISC/fix_imd.cpp
@@ -47,10 +47,6 @@ negotiate an appropriate license for such distribution."
    Justin Gullingsrud, and James Phillips, (TCBG, Beckman Institute, UIUC)
 ------------------------------------------------------------------------- */
 
-#ifdef LAMMPS_BIGBIG
-#error LAMMPS_BIGBIG not supported by this file
-#endif
-
 #include "fix_imd.h"
 #include "atom.h"
 #include "comm.h"
@@ -83,48 +79,51 @@ negotiate an appropriate license for such distribution."
 
 #include <errno.h>
 
+using namespace LAMMPS_NS;
+using namespace FixConst;
+
 /* re-usable integer hash table code with static linkage. */
 
 /** hash table top level data structure */
-typedef struct inthash_t {
-  struct inthash_node_t **bucket;        /* array of hash nodes */
-  int size;                           /* size of the array */
-  int entries;                        /* number of entries in table */
-  int downshift;                      /* shift cound, used in hash function */
-  int mask;                           /* used to select bits for hashing */
-} inthash_t;
+typedef struct taginthash_t {
+  struct taginthash_node_t **bucket; /* array of hash nodes */
+  tagint size;                       /* size of the array */
+  tagint entries;                    /* number of entries in table */
+  tagint downshift;                  /* shift count, used in hash function */
+  tagint mask;                       /* used to select bits for hashing */
+} taginthash_t;
 
 /** hash table node data structure */
-typedef struct inthash_node_t {
-  int data;                           /* data in hash node */
-  int key;                            /* key for hash lookup */
-  struct inthash_node_t *next;        /* next node in hash chain */
-} inthash_node_t;
+typedef struct taginthash_node_t {
+  tagint data;                           /* data in hash node */
+  tagint key;                            /* key for hash lookup */
+  struct taginthash_node_t *next;        /* next node in hash chain */
+} taginthash_node_t;
 
 #define HASH_FAIL  -1
 #define HASH_LIMIT  0.5
 
 /* initialize new hash table  */
-static void inthash_init(inthash_t *tptr, int buckets);
+static void taginthash_init(taginthash_t *tptr, tagint buckets);
 /* lookup entry in hash table */
-static int inthash_lookup(const inthash_t *tptr, int key);
+static tagint taginthash_lookup(const taginthash_t *tptr, tagint key);
 /* generate list of keys for reverse lookups. */
-static int *inthash_keys(inthash_t *tptr);
-/* insert an entry into hash table. */
-static int inthash_insert(inthash_t *tptr, int key, int data);
+static tagint *taginthash_keys(taginthash_t *tptr);
+/* insert an entry taginto hash table. */
+static tagint taginthash_insert(taginthash_t *tptr, tagint key, tagint data);
 /* delete the hash table */
-static void inthash_destroy(inthash_t *tptr);
+static void taginthash_destroy(taginthash_t *tptr);
 /* adapted sort for in-place sorting of map indices. */
-static void id_sort(int *idmap, int left, int right);
+static void id_sort(tagint *idmap, tagint left, tagint right);
 
 /************************************************************************
  * integer hash code:
  ************************************************************************/
 
-/* inthash() - Hash function returns a hash number for a given key.
+/* taginthash() - Hash function returns a hash number for a given key.
  * tptr: Pointer to a hash table, key: The key to create a hash number for */
-static int inthash(const inthash_t *tptr, int key) {
-  int hashvalue;
+static tagint taginthash(const taginthash_t *tptr, tagint key) {
+  tagint hashvalue;
 
   hashvalue = (((key*1103515249)>>tptr->downshift) & tptr->mask);
   if (hashvalue < 0) {
@@ -135,25 +134,25 @@ static int inthash(const inthash_t *tptr, int key) {
 }
 
 /*
- *  rebuild_table_int() - Create new hash table when old one fills up.
+ *  rebuild_table_tagint() - Create new hash table when old one fills up.
  *
  *  tptr: Pointer to a hash table
  */
-static void rebuild_table_int(inthash_t *tptr) {
-  inthash_node_t **old_bucket, *old_hash, *tmp;
-  int old_size, h, i;
+static void rebuild_table_tagint(taginthash_t *tptr) {
+  taginthash_node_t **old_bucket, *old_hash, *tmp;
+  tagint old_size, h, i;
 
   old_bucket=tptr->bucket;
   old_size=tptr->size;
 
   /* create a new table and rehash old buckets */
-  inthash_init(tptr, old_size<<1);
+  taginthash_init(tptr, old_size<<1);
   for (i=0; i<old_size; i++) {
     old_hash=old_bucket[i];
     while(old_hash) {
       tmp=old_hash;
       old_hash=old_hash->next;
-      h=inthash(tptr, tmp->key);
+      h=taginthash(tptr, tmp->key);
       tmp->next=tptr->bucket[h];
       tptr->bucket[h]=tmp;
       tptr->entries++;
@@ -167,12 +166,12 @@ static void rebuild_table_int(inthash_t *tptr) {
 }
 
 /*
- *  inthash_init() - Initialize a new hash table.
+ *  taginthash_init() - Initialize a new hash table.
  *
  *  tptr: Pointer to the hash table to initialize
  *  buckets: The number of initial buckets to create
  */
-void inthash_init(inthash_t *tptr, int buckets) {
+void taginthash_init(taginthash_t *tptr, tagint buckets) {
 
   /* make sure we allocate something */
   if (buckets==0)
@@ -192,25 +191,25 @@ void inthash_init(inthash_t *tptr, int buckets) {
   } /* while */
 
   /* allocate memory for table */
-  tptr->bucket=(inthash_node_t **) calloc(tptr->size, sizeof(inthash_node_t *));
+  tptr->bucket=(taginthash_node_t **) calloc(tptr->size, sizeof(taginthash_node_t *));
 
   return;
 }
 
 /*
- *  inthash_lookup() - Lookup an entry in the hash table and return a pointer to
+ *  taginthash_lookup() - Lookup an entry in the hash table and return a pointer to
  *    it or HASH_FAIL if it wasn't found.
  *
  *  tptr: Pointer to the hash table
  *  key: The key to lookup
  */
-int inthash_lookup(const inthash_t *tptr, int key) {
-  int h;
-  inthash_node_t *node;
+tagint taginthash_lookup(const taginthash_t *tptr, tagint key) {
+  tagint h;
+  taginthash_node_t *node;
 
 
   /* find the entry in the hash table */
-  h=inthash(tptr, key);
+  h=taginthash(tptr, key);
   for (node=tptr->bucket[h]; node!=NULL; node=node->next) {
     if (node->key == key)
       break;
@@ -222,17 +221,17 @@ int inthash_lookup(const inthash_t *tptr, int key) {
 
 
 /*
- *  inthash_keys() - Return a list of keys.
+ *  taginthash_keys() - Return a list of keys.
  *  NOTE: the returned list must be freed with free(3).
  */
-int *inthash_keys(inthash_t *tptr) {
+tagint *taginthash_keys(taginthash_t *tptr) {
 
-  int *keys;
-  inthash_node_t *node;
+  tagint *keys;
+  taginthash_node_t *node;
 
-  keys = (int *)calloc(tptr->entries, sizeof(int));
+  keys = (tagint *)calloc(tptr->entries, sizeof(tagint));
 
-  for (int i=0; i < tptr->size; ++i) {
+  for (tagint i=0; i < tptr->size; ++i) {
     for (node=tptr->bucket[i]; node != NULL; node=node->next) {
       keys[node->data] = node->key;
     }
@@ -242,29 +241,29 @@ int *inthash_keys(inthash_t *tptr) {
 }
 
 /*
- *  inthash_insert() - Insert an entry into the hash table.  If the entry already
+ *  taginthash_insert() - Insert an entry into the hash table.  If the entry already
  *  exists return a pointer to it, otherwise return HASH_FAIL.
  *
  *  tptr: A pointer to the hash table
  *  key: The key to insert into the hash table
  *  data: A pointer to the data to insert into the hash table
  */
-int inthash_insert(inthash_t *tptr, int key, int data) {
-  int tmp;
-  inthash_node_t *node;
-  int h;
+tagint taginthash_insert(taginthash_t *tptr, tagint key, tagint data) {
+  tagint tmp;
+  taginthash_node_t *node;
+  tagint h;
 
   /* check to see if the entry exists */
-  if ((tmp=inthash_lookup(tptr, key)) != HASH_FAIL)
+  if ((tmp=taginthash_lookup(tptr, key)) != HASH_FAIL)
     return(tmp);
 
   /* expand the table if needed */
   while (tptr->entries>=HASH_LIMIT*tptr->size)
-    rebuild_table_int(tptr);
+    rebuild_table_tagint(tptr);
 
   /* insert the new entry */
-  h=inthash(tptr, key);
-  node=(struct inthash_node_t *) malloc(sizeof(inthash_node_t));
+  h=taginthash(tptr, key);
+  node=(struct taginthash_node_t *) malloc(sizeof(taginthash_node_t));
   node->data=data;
   node->key=key;
   node->next=tptr->bucket[h];
@@ -275,12 +274,12 @@ int inthash_insert(inthash_t *tptr, int key, int data) {
 }
 
 /*
- * inthash_destroy() - Delete the entire table, and all remaining entries.
+ * taginthash_destroy() - Delete the entire table, and all remaining entries.
  *
  */
-void inthash_destroy(inthash_t *tptr) {
-  inthash_node_t *node, *last;
-  int i;
+void taginthash_destroy(taginthash_t *tptr) {
+  taginthash_node_t *node, *last;
+  tagint i;
 
   for (i=0; i<tptr->size; i++) {
     node = tptr->bucket[i];
@@ -294,18 +293,18 @@ void inthash_destroy(inthash_t *tptr) {
   /* free the entire array of buckets */
   if (tptr->bucket != NULL) {
     free(tptr->bucket);
-    memset(tptr, 0, sizeof(inthash_t));
+    memset(tptr, 0, sizeof(taginthash_t));
   }
 }
 
 /************************************************************************
- * integer list sort code:
+ * taginteger list sort code:
  ************************************************************************/
 
-/* sort for integer map. initial call  id_sort(idmap, 0, natoms - 1); */
-static void id_sort(int *idmap, int left, int right)
+/* sort for taginteger map. initial call  id_sort(idmap, 0, natoms - 1); */
+static void id_sort(tagint *idmap, tagint left, tagint right)
 {
-  int pivot, l_hold, r_hold;
+  tagint pivot, l_hold, r_hold;
 
   l_hold = left;
   r_hold = right;
@@ -433,12 +432,9 @@ static void  imdsock_destroy(void *);
  * The implementation follows at the end of the file.          *
  ***************************************************************/
 
-using namespace LAMMPS_NS;
-using namespace FixConst;
-
 /* struct for packed data communication of coordinates and forces. */
 struct commdata {
-  int tag;
+  tagint tag;
   float x,y,z;
 };
 
@@ -580,10 +576,10 @@ FixIMD::~FixIMD()
   }
 #endif
 
-  inthash_t *hashtable = (inthash_t *)idmap;
+  taginthash_t *hashtable = (taginthash_t *)idmap;
   memory->destroy(comm_buf);
   memory->destroy(force_buf);
-  inthash_destroy(hashtable);
+  taginthash_destroy(hashtable);
   delete hashtable;
   free(rev_idmap);
   // close sockets
@@ -626,12 +622,13 @@ int FixIMD::reconnect()
 
   if (me == 0) {
     if (clientsock) return 1;
-    if (screen && connect_msg)
-      if (nowait_flag)
+    if (screen && connect_msg) {
+      if (nowait_flag) {
         fprintf(screen,"Listening for IMD connection on port %d. Transfer rate %d.\n",imd_port, imd_trate);
-      else
+      } else {
         fprintf(screen,"Waiting for IMD connection on port %d. Transfer rate %d.\n",imd_port, imd_trate);
-
+      }
+    }
     connect_msg = 0;
     clientsock = NULL;
     if (nowait_flag) {
@@ -693,7 +690,7 @@ void FixIMD::setup(int)
   int i,j;
   int nmax,nme,nlocal;
   int *mask  = atom->mask;
-  int *tag  = atom->tag;
+  tagint *tag  = atom->tag;
   nlocal = atom->nlocal;
   nme=0;
   for (i=0; i < nlocal; ++i)
@@ -712,8 +709,8 @@ void FixIMD::setup(int)
     error->all(FLERR,"LAMMPS terminated on error in setting up IMD connection.");
 
   /* initialize and build hashtable. */
-  inthash_t *hashtable=new inthash_t;
-  inthash_init(hashtable, num_coords);
+  taginthash_t *hashtable=new taginthash_t;
+  taginthash_init(hashtable, num_coords);
   idmap = (void *)hashtable;
 
   MPI_Status status;
@@ -722,7 +719,7 @@ void FixIMD::setup(int)
   struct commdata *buf = static_cast<struct commdata *>(comm_buf);
 
   if (me == 0) {
-    int *taglist = new int[num_coords];
+    tagint *taglist = new tagint[num_coords];
     int numtag=0; /* counter to map atom tags to a 0-based consecutive index list */
 
     for (i=0; i < nlocal; ++i) {
@@ -750,13 +747,13 @@ void FixIMD::setup(int)
      * same list when running in parallel and build hash table. */
     id_sort(taglist, 0, num_coords-1);
     for (i=0; i < num_coords; ++i) {
-      inthash_insert(hashtable, taglist[i], i);
+      taginthash_insert(hashtable, taglist[i], i);
     }
     delete[] taglist;
 
     /* generate reverse index-to-tag map for communicating
      * IMD forces back to the proper atoms */
-    rev_idmap=inthash_keys(hashtable);
+    rev_idmap=taginthash_keys(hashtable);
   } else {
     nme=0;
     for (i=0; i < nlocal; ++i) {
@@ -827,7 +824,7 @@ void FixIMD::post_force(int vflag)
       return;     /* IMD client has detached and not yet come back. do nothing. */
   }
 
-  int *tag = atom->tag;
+  tagint *tag = atom->tag;
   double **x = atom->x;
   imageint *image = atom->image;
   int nlocal = atom->nlocal;
@@ -1040,8 +1037,8 @@ void FixIMD::post_force(int vflag)
 
       for (i=0; i<nlocal; ++i) {
         if (mask[i] & groupbit) {
-          const int j = 3*inthash_lookup((inthash_t *)idmap, tag[i]);
-          if (j != HASH_FAIL) {
+          const tagint j = 3*taginthash_lookup((taginthash_t *)idmap, tag[i]);
+          if (j != 3*HASH_FAIL) {
             int ix = (image[i] & IMGMASK) - IMGMAX;
             int iy = (image[i] >> IMGBITS & IMGMASK) - IMGMAX;
             int iz = (image[i] >> IMG2BITS) - IMGMAX;
@@ -1061,8 +1058,8 @@ void FixIMD::post_force(int vflag)
     } else {
       for (i=0; i<nlocal; ++i) {
         if (mask[i] & groupbit) {
-          const int j = 3*inthash_lookup((inthash_t *)idmap, tag[i]);
-          if (j != HASH_FAIL) {
+          const tagint j = 3*taginthash_lookup((taginthash_t *)idmap, tag[i]);
+          if (j != 3*HASH_FAIL) {
             recvcoord[j]   = x[i][0];
             recvcoord[j+1] = x[i][1];
             recvcoord[j+2] = x[i][2];
@@ -1080,8 +1077,8 @@ void FixIMD::post_force(int vflag)
       ndata /= size_one;
 
       for (k=0; k<ndata; ++k) {
-        const int j = 3*inthash_lookup((inthash_t *)idmap, buf[k].tag);
-        if (j != HASH_FAIL) {
+        const tagint j = 3*taginthash_lookup((taginthash_t *)idmap, buf[k].tag);
+        if (j != 3*HASH_FAIL) {
           recvcoord[j]   = buf[k].x;
           recvcoord[j+1] = buf[k].y;
           recvcoord[j+2] = buf[k].z;
diff --git a/src/USER-MISC/fix_imd.h b/src/USER-MISC/fix_imd.h
index 379742fb4d..a2f955b12d 100644
--- a/src/USER-MISC/fix_imd.h
+++ b/src/USER-MISC/fix_imd.h
@@ -82,7 +82,7 @@ class FixIMD : public Fix {
   int    maxbuf;                // size of atom communication buffer.
   void  *comm_buf;              // communication buffer
   void  *idmap;                 // hash for mapping atom indices to consistent order.
-  int   *rev_idmap;             // list of the hash keys for reverse mapping.
+  tagint *rev_idmap;            // list of the hash keys for reverse mapping.
 
   int    imd_forces;            // number of forces communicated via IMD.
   void  *force_buf;             // force data buffer
diff --git a/src/USER-MOLFILE/dump_molfile.cpp b/src/USER-MOLFILE/dump_molfile.cpp
index 753caf3d39..f3542acce7 100644
--- a/src/USER-MOLFILE/dump_molfile.cpp
+++ b/src/USER-MOLFILE/dump_molfile.cpp
@@ -15,10 +15,6 @@
    Contributing author: Axel Kohlmeyer (Temple U)
 ------------------------------------------------------------------------- */
 
-#ifdef LAMMPS_BIGBIG
-#error LAMMPS_BIGBIG not supported by this file
-#endif
-
 #include <stdio.h>
 #include <string.h>
 #include <math.h>
@@ -305,11 +301,11 @@ void DumpMolfile::openfile()
 
 /* ---------------------------------------------------------------------- */
 
-void DumpMolfile::pack(int *ids)
+void DumpMolfile::pack(tagint *ids)
 {
   int m,n;
 
-  int *tag = atom->tag;
+  tagint *tag = atom->tag;
   int *type = atom->type;
   double **x = atom->x;
   imageint *image = atom->image;
diff --git a/src/USER-MOLFILE/dump_molfile.h b/src/USER-MOLFILE/dump_molfile.h
index d14b4f58c4..c99d1cc5ea 100644
--- a/src/USER-MOLFILE/dump_molfile.h
+++ b/src/USER-MOLFILE/dump_molfile.h
@@ -49,7 +49,7 @@ class DumpMolfile : public Dump {
   virtual void init_style();
   virtual int modify_param(int, char **);
   virtual void write_header(bigint) {};
-  virtual void pack(int *);
+  virtual void pack(tagint *);
   virtual void write_data(int, double *);
   virtual bigint memory_usage();
   virtual void openfile();