diff --git a/src/delete_atoms.cpp b/src/delete_atoms.cpp
index 7088eb576e..ce881b4d0d 100644
--- a/src/delete_atoms.cpp
+++ b/src/delete_atoms.cpp
@@ -43,7 +43,6 @@ void DeleteAtoms::command(int narg, char **arg)
     error->all("Cannot use delete_atoms unless atoms have IDs");
 
   int natoms_previous = static_cast<int> (atom->natoms);
-  int tag_lowest = natoms_previous + 1;
 
   // allocate and initialize deletion list
   
@@ -53,7 +52,6 @@ void DeleteAtoms::command(int narg, char **arg)
   for (int i = 0; i < nlocal; i++) list[i] = 0;
 
   // delete the atoms
-  // return tag_lowest = min tag of each proc's deleted atoms
 
   if (strcmp(arg[0],"group") == 0) delete_group(narg,arg,list);
   else if (strcmp(arg[0],"region") == 0) delete_region(narg,arg,list);
@@ -62,14 +60,12 @@ void DeleteAtoms::command(int narg, char **arg)
 
   // delete local atoms in list
   // reset nlocal
-  // tag_lowest_all = smallest deleted atom tag on any proc
 
   int *tag = atom->tag;
 
   int i = 0;
   while (i < nlocal) {
     if (list[i]) {
-      tag_lowest = MIN(tag_lowest,tag[i]);
       atom->copy(nlocal-1,i);
       list[i] = list[nlocal-1];
       nlocal--;
@@ -78,19 +74,14 @@ void DeleteAtoms::command(int narg, char **arg)
   atom->nlocal = nlocal;
   delete [] list;
 
-  int tag_lowest_all;
-  MPI_Allreduce(&tag_lowest,&tag_lowest_all,1,MPI_INT,MPI_MIN,world);
-
   // if non-molecular system, reset atom tags to be contiguous
-  // set all atom IDs >= tag_lowest_all to 0
-  // tag_extend() will reset tags for those atoms
+  // set all atom IDs to 0, call tag_extend()
 
   if (atom->molecular == 0) {
     int *tag = atom->tag;
     int nlocal = atom->nlocal;
  
-    for (i = 0; i < nlocal; i++)
-      if (tag[i] >= tag_lowest_all) tag[i] = 0;
+    for (i = 0; i < nlocal; i++) tag[i] = 0;
     atom->tag_extend();
   }
 
@@ -188,14 +179,17 @@ void DeleteAtoms::delete_overlap(int narg, char **arg, int *list)
 
   // init entire system since comm->borders and neighbor->build is done
   // comm::init needs neighbor::init needs pair::init needs kspace::init, etc
+  // set half_command since will require half neigh list even if
+  //   neighbor would otherwise not create one, then unset it
 
   if (comm->me == 0 && screen)
     fprintf(screen,"System init for delete_atoms ...\n");
+  neighbor->half_command = 1;
   sys->init();
+  neighbor->half_command = 0;
 
   // setup domain, communication and neighboring
   // acquire ghosts
-  // build half neighbor list via explicit call
     
   domain->pbc();
   domain->reset_box();
@@ -204,8 +198,11 @@ void DeleteAtoms::delete_overlap(int narg, char **arg, int *list)
   comm->exchange();
   comm->borders();
 
-  if (!neighbor->half) neighbor->build_half_setup();
-  neighbor->build_half();
+  // call to build() forces memory allocation for neighbor lists
+  // build half list explicitly if build() doesn't do it
+
+  neighbor->build();
+  if (!neighbor->half_every) neighbor->build_half();
 
   // error check on cutoff
 
@@ -289,10 +286,6 @@ void DeleteAtoms::delete_overlap(int narg, char **arg, int *list)
     }
   }
 
-  // cleanup after neighbor list
-
-  if (!neighbor->half) neighbor->build_half_cleanup();
-
   // delete temporary atom map
 
   if (mapflag) {
diff --git a/src/neighbor.cpp b/src/neighbor.cpp
index 36464b26d2..932195bf77 100644
--- a/src/neighbor.cpp
+++ b/src/neighbor.cpp
@@ -87,7 +87,7 @@ Neighbor::Neighbor()
 
   // half neighbor list info
 
-  half = 0;
+  half = half_command = 0;
   maxpage = 0;
   numneigh = NULL;
   firstneigh = NULL;
@@ -385,8 +385,9 @@ void Neighbor::init()
   }
 
   half = full = 0;
-  if (half_every || half_once) half = 1;
+  if (half_every || half_once || half_command) half = 1;
   if (full_every || full_once) full = 1;
+  half = 1;
 
   // setup/delete memory for half and full lists
 
@@ -720,7 +721,7 @@ void Neighbor::build()
 
   // extend atom arrays if necessary
   // check half/full instead of half_every/full_every so memory will be
-  //   allocated correctly when build_half() and build_full() are called
+  //   allocated correctly whenever build_half() and build_full() are called
 
   if (atom->nlocal > maxlocal) {
     maxlocal = atom->nmax;
@@ -792,27 +793,6 @@ void Neighbor::build()
   }
 }
 
-/* ----------------------------------------------------------------------
-   prepare for one-time call to build a half neighbor list
-   only needs to be called if Neighbor::init() set half = 0
-------------------------------------------------------------------------- */
-
-void Neighbor::build_half_setup()
-{
-  numneigh = (int *) memory->smalloc(maxlocal*sizeof(int),"neigh:numneigh");
-  firstneigh =
-    (int **) memory->smalloc(maxlocal*sizeof(int *),"neigh:firstneigh");
-  add_pages(0);
-
-  if (style == 0) {
-    if (force->newton_pair == 0) half_build = &Neighbor::half_nsq_no_newton;
-    else half_build = &Neighbor::half_nsq_newton;
-  } else if (style == 1) {
-    if (force->newton_pair == 0) half_build = &Neighbor::half_bin_no_newton;
-    else half_build = &Neighbor::half_bin_newton;
-  }
-}
-
 /* ----------------------------------------------------------------------
    one-time call to build a half neighbor list made by other classes
 ------------------------------------------------------------------------- */
@@ -823,23 +803,7 @@ void Neighbor::build_half()
 }
 
 /* ----------------------------------------------------------------------
-   clean-up from one-time call to build a half neighbor list
-   only needs to be called if Neighbor::init() set half = 0
-------------------------------------------------------------------------- */
-
-void Neighbor::build_half_cleanup()
-{
-  memory->sfree(numneigh);
-  memory->sfree(firstneigh);
-  for (int i = 0; i < maxpage; i++) memory->sfree(pages[i]);
-  memory->sfree(pages);
-  pages = NULL;
-  maxpage = 0;
-  half_build = NULL;
-}
-
-/* ----------------------------------------------------------------------
-   build a full neighbor list, called occasionally by a fix
+   one-time call to build a full neighbor list made by other classes
 ------------------------------------------------------------------------- */
 
 void Neighbor::build_full()
diff --git a/src/neighbor.h b/src/neighbor.h
index 8ee4111d98..f41436d74f 100644
--- a/src/neighbor.h
+++ b/src/neighbor.h
@@ -39,6 +39,7 @@ class Neighbor : public LAMMPS {
   int full_every;                  // 0/1 if full list built every step
   int half_once;                   // 0/1 if half pair list built occasionally
   int full_once;                   // 0/1 if full pair list built occasionally
+  int half_command;                // 0/1 if command requires half list
 
   int *numneigh;                   // # of half neighbors for each atom
   int **firstneigh;                // ptr to 1st half neighbor of each atom
@@ -74,9 +75,7 @@ class Neighbor : public LAMMPS {
   int check_distance();       // check max distance moved since last build
   void setup_bins();          // setup bins based on box and cutoff
   void build();               // create all neighbor lists (half,full,bond)
-  void build_half_setup();    // setup for one-time creation of half list
   void build_half();          // one-time creation of half neighbor list
-  void build_half_cleanup();  // cleanup of one-time creation of half list
   void build_full();          // one-time creation of full neighbor list
   void modify_params(int, char**);  // modify parameters of neighbor build
   int memory_usage();         // tally memory usage
diff --git a/src/pressure.cpp b/src/pressure.cpp
index 49d6e71000..857510ec9c 100644
--- a/src/pressure.cpp
+++ b/src/pressure.cpp
@@ -150,7 +150,7 @@ void Pressure::compute(Temperature *temperature)
 
   double inv_volume = 1.0 / (domain->xprd * domain->yprd * domain->zprd);
 
-  if (force->pair->tail_flag)
+  if (force->pair && force->pair->tail_flag)
     for (i = 0; i < n; i++) virial[i] += force->pair->ptail * inv_volume;
 
   // compute just total average pressure or entire pressure tensor
diff --git a/src/thermo.cpp b/src/thermo.cpp
index d46678e466..27b5890932 100644
--- a/src/thermo.cpp
+++ b/src/thermo.cpp
@@ -837,7 +837,7 @@ void Thermo::compute_pe()
   MPI_Allreduce(&tmp,&dvalue,1,MPI_DOUBLE,MPI_SUM,world);
 
   if (force->kspace) dvalue += force->kspace->energy;
-  if (force->pair->tail_flag) {
+  if (force->pair && force->pair->tail_flag) {
     double volume = domain->xprd * domain->yprd * domain->zprd;
     dvalue += force->pair->etail / volume;
   }
@@ -881,7 +881,7 @@ void Thermo::compute_evdwl()
 
   MPI_Allreduce(&tmp,&dvalue,1,MPI_DOUBLE,MPI_SUM,world);
 
-  if (force->pair->tail_flag) {
+  if (force->pair && force->pair->tail_flag) {
     double volume = domain->xprd * domain->yprd * domain->zprd;
     dvalue += force->pair->etail / volume;
   }
@@ -912,7 +912,7 @@ void Thermo::compute_epair()
   MPI_Allreduce(&tmp,&dvalue,1,MPI_DOUBLE,MPI_SUM,world);
 
   if (force->kspace) dvalue += force->kspace->energy;
-  if (force->pair->tail_flag) {
+  if (force->pair && force->pair->tail_flag) {
     double volume = domain->xprd * domain->yprd * domain->zprd;
     dvalue += force->pair->etail / volume;
   }
@@ -993,7 +993,7 @@ void Thermo::compute_elong()
 
 void Thermo::compute_etail()
 {
-  if (force->pair->tail_flag) {
+  if (force->pair && force->pair->tail_flag) {
     double volume = domain->xprd * domain->yprd * domain->zprd;
     dvalue = force->pair->etail / volume;
     if (normflag) dvalue /= natoms;