diff --git a/src/GPU/Package.sh b/src/GPU/Package.sh
index e62e0be8fd..cdac230d51 100644
--- a/src/GPU/Package.sh
+++ b/src/GPU/Package.sh
@@ -1,6 +1,6 @@
 # Update package files in LAMMPS
 # cp package file to src if doesn't exist or is different
-# do not copy gayberne files if non-GPU version does not exist
+# do not copy dependent files if non-GPU version does not exist
 
 for file in *.cpp *.h; do
   if (test $file = pair_gayberne_gpu.cpp -a ! -e ../pair_gayberne.cpp) then
diff --git a/src/OPT/Package.sh b/src/OPT/Package.sh
index a1714684fc..5fb182c0f9 100644
--- a/src/OPT/Package.sh
+++ b/src/OPT/Package.sh
@@ -1,6 +1,6 @@
 # Update package files in LAMMPS
 # cp package file to src if doesn't exist or is different
-# do not copy eam and charmm files if non-OPT versions do not exist
+# do not copy dependent files if non-OPT versions do not exist
 
 for file in *.cpp *.h; do
   if (test $file = pair_eam_opt.cpp -a ! -e ../pair_eam.cpp) then
diff --git a/src/PERI/pair_peri_lps.cpp b/src/PERI/pair_peri_lps.cpp
index 70d3530c6b..a553bf89be 100644
--- a/src/PERI/pair_peri_lps.cpp
+++ b/src/PERI/pair_peri_lps.cpp
@@ -421,12 +421,11 @@ void PairPeriLPS::init_style()
 {
   // error checks
 
-  if (!atom->peri_flag)  error->all(FLERR,"Pair style peri requires atom style peri");
+  if (!atom->peri_flag)
+    error->all(FLERR,"Pair style peri requires atom style peri");
   if (atom->map_style == 0)
     error->all(FLERR,"Pair peri requires an atom map, see atom_modify");
 
-  if (domain->lattice == NULL)
-    error->all(FLERR,"Pair peri requires a lattice be defined");
   if (domain->lattice->xlattice != domain->lattice->ylattice ||
       domain->lattice->xlattice != domain->lattice->zlattice ||
       domain->lattice->ylattice != domain->lattice->zlattice)
diff --git a/src/PERI/pair_peri_pmb.cpp b/src/PERI/pair_peri_pmb.cpp
index 38f14d7b53..501c14a121 100644
--- a/src/PERI/pair_peri_pmb.cpp
+++ b/src/PERI/pair_peri_pmb.cpp
@@ -359,12 +359,11 @@ void PairPeriPMB::init_style()
 {
   // error checks
 
-  if (!atom->peri_flag) error->all(FLERR,"Pair style peri requires atom style peri");
+  if (!atom->peri_flag) 
+    error->all(FLERR,"Pair style peri requires atom style peri");
   if (atom->map_style == 0)
     error->all(FLERR,"Pair peri requires an atom map, see atom_modify");
 
-  if (domain->lattice == NULL)
-    error->all(FLERR,"Pair peri requires a lattice be defined");
   if (domain->lattice->xlattice != domain->lattice->ylattice ||
       domain->lattice->xlattice != domain->lattice->zlattice ||
       domain->lattice->ylattice != domain->lattice->zlattice)
diff --git a/src/SHOCK/fix_append_atoms.cpp b/src/SHOCK/fix_append_atoms.cpp
index 8c7018c84b..b6095e420e 100644
--- a/src/SHOCK/fix_append_atoms.cpp
+++ b/src/SHOCK/fix_append_atoms.cpp
@@ -60,7 +60,7 @@ FixAppendAtoms::FixAppendAtoms(LAMMPS *lmp, int narg, char **arg) :
   randomx = NULL;
   randomt = NULL;
 
-  if (!domain->lattice) 
+  if (domain->lattice->nbasis == 0)
     error->all(FLERR,"Fix append/atoms requires a lattice be defined");
 
   nbasis = domain->lattice->nbasis;
@@ -126,12 +126,10 @@ FixAppendAtoms::FixAppendAtoms(LAMMPS *lmp, int narg, char **arg) :
       iarg += 3;
     } else if (strcmp(arg[iarg],"basis") == 0) {
       if (iarg+3 > narg) error->all(FLERR,"Illegal fix append/atoms command");
-      if (domain->lattice == NULL)
-        error->all(FLERR,"Fix append/atoms requires a lattice be defined");
       int ibasis = atoi(arg[iarg+1]);
       int itype = atoi(arg[iarg+2]);
       if (ibasis <= 0 || ibasis > nbasis || itype <= 0 || itype > atom->ntypes)
-        error->all(FLERR,"Illegal fix append/atoms command");
+        error->all(FLERR,"Invalid basis setting in fix append/atoms command");
       basistype[ibasis-1] = itype;
       iarg += 3;
     } else if (strcmp(arg[iarg],"size") == 0) {
@@ -184,9 +182,6 @@ FixAppendAtoms::FixAppendAtoms(LAMMPS *lmp, int narg, char **arg) :
 
   // setup scaling
 
-  if (scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of fix append/atoms with undefined lattice");
-
   double xscale,yscale,zscale;
   if (scaleflag) {
     xscale = domain->lattice->xlattice;
diff --git a/src/SHOCK/fix_wall_piston.cpp b/src/SHOCK/fix_wall_piston.cpp
index 18d097d97b..e8686c197d 100644
--- a/src/SHOCK/fix_wall_piston.cpp
+++ b/src/SHOCK/fix_wall_piston.cpp
@@ -140,9 +140,6 @@ FixWallPiston::FixWallPiston(LAMMPS *lmp, int narg, char **arg) :
 
   // setup scaling
 
-  if (scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of fix wall/piston with undefined lattice");
-
   double xscale,yscale,zscale;
   if (scaleflag) {
     xscale = domain->lattice->xlattice;
diff --git a/src/SRD/fix_wall_srd.cpp b/src/SRD/fix_wall_srd.cpp
index cd3b8df437..2fd302c601 100644
--- a/src/SRD/fix_wall_srd.cpp
+++ b/src/SRD/fix_wall_srd.cpp
@@ -127,9 +127,6 @@ FixWallSRD::FixWallSRD(LAMMPS *lmp, int narg, char **arg) :
     if (wallstyle[m] == CONSTANT) flag = 1;
 
   if (flag) {
-    if (scaleflag && domain->lattice == NULL)
-      error->all(FLERR,"Use of fix wall with undefined lattice");
-
     double xscale,yscale,zscale;
     if (scaleflag) {
       xscale = domain->lattice->xlattice;
diff --git a/src/USER-MOLFILE/Package.sh b/src/USER-MOLFILE/Package.sh
index f4e52b70d7..3f6db2b877 100644
--- a/src/USER-MOLFILE/Package.sh
+++ b/src/USER-MOLFILE/Package.sh
@@ -1,5 +1,6 @@
 # Update package files in LAMMPS
 # copy package file to src if it doesn't exists or is different
+
 for file in molfile_interface.cpp molfile_interface.h molfile_plugin.h \
     dump_molfile.cpp dump_molfile.h reader_molfile.h reader_molfile.cpp \
     vmdplugin.h ; do \
diff --git a/src/change_box.cpp b/src/change_box.cpp
index 2ff513b570..9da5535237 100644
--- a/src/change_box.cpp
+++ b/src/change_box.cpp
@@ -185,9 +185,6 @@ void ChangeBox::command(int narg, char **arg)
   for (int i = 0; i < nops; i++)
     if (ops[i].style == FINAL || ops[i].style == DELTA) flag = 1;
 
-  if (flag && scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of change_box with undefined lattice");
-
   if (flag && scaleflag) {
     scale[0] = domain->lattice->xlattice;
     scale[1] = domain->lattice->ylattice;
diff --git a/src/compute_temp_ramp.cpp b/src/compute_temp_ramp.cpp
index b96467da6d..f2636b1adc 100644
--- a/src/compute_temp_ramp.cpp
+++ b/src/compute_temp_ramp.cpp
@@ -59,9 +59,6 @@ ComputeTempRamp::ComputeTempRamp(LAMMPS *lmp, int narg, char **arg) :
 
   // setup scaling
 
-  if (scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of compute temp/ramp with undefined lattice");
-
   if (scaleflag) {
     xscale = domain->lattice->xlattice;
     yscale = domain->lattice->ylattice;
diff --git a/src/create_atoms.cpp b/src/create_atoms.cpp
index 45cb6ac183..336d18fe2f 100644
--- a/src/create_atoms.cpp
+++ b/src/create_atoms.cpp
@@ -91,22 +91,18 @@ void CreateAtoms::command(int narg, char **arg)
   int scaleflag = 1;
   remapflag = 0;
 
-  if (domain->lattice) {
-    nbasis = domain->lattice->nbasis;
-    basistype = new int[nbasis];
-    for (int i = 0; i < nbasis; i++) basistype[i] = itype;
-  }
+  nbasis = domain->lattice->nbasis;
+  basistype = new int[nbasis];
+  for (int i = 0; i < nbasis; i++) basistype[i] = itype;
 
   while (iarg < narg) {
     if (strcmp(arg[iarg],"basis") == 0) {
       if (iarg+3 > narg) error->all(FLERR,"Illegal create_atoms command");
-      if (domain->lattice == NULL)
-        error->all(FLERR,"Cannot create atoms with undefined lattice");
       int ibasis = atoi(arg[iarg+1]);
       itype = atoi(arg[iarg+2]);
       if (ibasis <= 0 || ibasis > nbasis ||
           itype <= 0 || itype > atom->ntypes)
-        error->all(FLERR,"Illegal create_atoms command");
+        error->all(FLERR,"Invalid basis setting in create_atoms command");
       basistype[ibasis-1] = itype;
       iarg += 3;
     } else if (strcmp(arg[iarg],"remap") == 0) {
@@ -131,18 +127,16 @@ void CreateAtoms::command(int narg, char **arg)
     if (seed <= 0) error->all(FLERR,"Illegal create_atoms command");
   }
 
-  // demand lattice be defined
-  // else setup scaling for single atom
+  // demand non-none lattice be defined for BOX and REGION
+  // else setup scaling for SINGLE and RANDOM
   // could use domain->lattice->lattice2box() to do conversion of
   //   lattice to box, but not consistent with other uses of units=lattice
   // triclinic remapping occurs in add_single()
 
   if (style == BOX || style == REGION) {
-    if (domain->lattice == NULL)
+    if (nbasis == 0)
       error->all(FLERR,"Cannot create atoms with undefined lattice");
   } else if (scaleflag == 1) {
-    if (domain->lattice == NULL)
-      error->all(FLERR,"Cannot create atoms with undefined lattice");
     xone[0] *= domain->lattice->xlattice;
     xone[1] *= domain->lattice->ylattice;
     xone[2] *= domain->lattice->zlattice;
diff --git a/src/displace_atoms.cpp b/src/displace_atoms.cpp
index 2f26f46b93..d9f5ce55c0 100644
--- a/src/displace_atoms.cpp
+++ b/src/displace_atoms.cpp
@@ -77,9 +77,6 @@ void DisplaceAtoms::command(int narg, char **arg)
 
   // setup scaling
 
-  if (scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of displace_atoms with undefined lattice");
-
   double xscale,yscale,zscale;
   if (scaleflag) {
     xscale = domain->lattice->xlattice;
diff --git a/src/domain.cpp b/src/domain.cpp
index ab0c918c9e..cbfd7fec82 100644
--- a/src/domain.cpp
+++ b/src/domain.cpp
@@ -85,6 +85,11 @@ Domain::Domain(LAMMPS *lmp) : Pointers(lmp)
   boxhi_lamda[0] = boxhi_lamda[1] = boxhi_lamda[2] = 1.0;
 
   lattice = NULL;
+  char **args = new char*[2];
+  args[0] = (char *) "none";
+  args[1] = (char *) "1.0";
+  set_lattice(2,args);
+
   nregion = maxregion = 0;
   regions = NULL;
 }
@@ -1229,17 +1234,12 @@ void Domain::image_flip(int m, int n, int p)
 
 /* ----------------------------------------------------------------------
    create a lattice
-   delete it if style = none
 ------------------------------------------------------------------------- */
 
 void Domain::set_lattice(int narg, char **arg)
 {
   if (lattice) delete lattice;
   lattice = new Lattice(lmp,narg,arg);
-  if (lattice->style == 0) {
-    delete lattice;
-    lattice = NULL;
-  }
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/fix_ave_spatial.cpp b/src/fix_ave_spatial.cpp
index 66c8ab30d5..6cfb753ffd 100644
--- a/src/fix_ave_spatial.cpp
+++ b/src/fix_ave_spatial.cpp
@@ -340,9 +340,6 @@ FixAveSpatial::FixAveSpatial(LAMMPS *lmp, int narg, char **arg) :
     error->all(FLERR,
                "Fix ave/spatial for triclinic boxes requires units reduced");
 
-  if (scaleflag == LATTICE && domain->lattice == NULL)
-    error->all(FLERR,"Use of fix ave/spatial with undefined lattice");
-
   if (scaleflag == LATTICE) {
     xscale = domain->lattice->xlattice;
     yscale = domain->lattice->ylattice;
diff --git a/src/fix_deform.cpp b/src/fix_deform.cpp
index c622c3b589..78b5e99313 100644
--- a/src/fix_deform.cpp
+++ b/src/fix_deform.cpp
@@ -256,9 +256,6 @@ FixDeform::FixDeform(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
     if (set[i].style == FINAL || set[i].style == DELTA ||
         set[i].style == VEL || set[i].style == WIGGLE) flag = 1;
 
-  if (flag && scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of fix deform with undefined lattice");
-
   double xscale,yscale,zscale;
   if (flag && scaleflag) {
     xscale = domain->lattice->xlattice;
diff --git a/src/fix_deposit.cpp b/src/fix_deposit.cpp
index 1bc91e13ae..c708a8fdbe 100644
--- a/src/fix_deposit.cpp
+++ b/src/fix_deposit.cpp
@@ -98,9 +98,6 @@ FixDeposit::FixDeposit(LAMMPS *lmp, int narg, char **arg) :
 
   // setup scaling
 
-  if (scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of fix deposit with undefined lattice");
-
   double xscale,yscale,zscale;
   if (scaleflag) {
     xscale = domain->lattice->xlattice;
diff --git a/src/fix_dt_reset.cpp b/src/fix_dt_reset.cpp
index 79e9441f6b..553e6ee04d 100644
--- a/src/fix_dt_reset.cpp
+++ b/src/fix_dt_reset.cpp
@@ -83,8 +83,6 @@ FixDtReset::FixDtReset(LAMMPS *lmp, int narg, char **arg) :
 
   // setup scaling, based on xlattice parameter
 
-  if (scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of fix dt/reset with undefined lattice");
   if (scaleflag) xmax *= domain->lattice->xlattice;
 
   // initializations
diff --git a/src/fix_indent.cpp b/src/fix_indent.cpp
index 6f4700c2ad..558121697b 100644
--- a/src/fix_indent.cpp
+++ b/src/fix_indent.cpp
@@ -59,9 +59,6 @@ FixIndent::FixIndent(LAMMPS *lmp, int narg, char **arg) :
 
   // setup scaling
 
-  if (scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of fix indent with undefined lattice");
-
   double xscale,yscale,zscale;
   if (scaleflag) {
     xscale = domain->lattice->xlattice;
diff --git a/src/fix_move.cpp b/src/fix_move.cpp
index e00c8e3063..0e241b8882 100644
--- a/src/fix_move.cpp
+++ b/src/fix_move.cpp
@@ -192,9 +192,6 @@ FixMove::FixMove(LAMMPS *lmp, int narg, char **arg) :
 
   if ((mstyle == LINEAR || mstyle == WIGGLE || mstyle == ROTATE) &&
       scaleflag) {
-    if (domain->lattice == NULL)
-      error->all(FLERR,"Use of fix move with undefined lattice");
-
     double xscale,yscale,zscale;
     if (scaleflag) {
       xscale = domain->lattice->xlattice;
diff --git a/src/fix_recenter.cpp b/src/fix_recenter.cpp
index dbdbb19744..50ea9c2303 100644
--- a/src/fix_recenter.cpp
+++ b/src/fix_recenter.cpp
@@ -75,9 +75,6 @@ FixRecenter::FixRecenter(LAMMPS *lmp, int narg, char **arg) :
 
   // scale xcom,ycom,zcom
 
-  if (scaleflag == LATTICE && domain->lattice == NULL)
-    error->all(FLERR,"Use of fix recenter with undefined lattice");
-
   double xscale,yscale,zscale;
   if (scaleflag == LATTICE) {
     xscale = domain->lattice->xlattice;
diff --git a/src/fix_wall.cpp b/src/fix_wall.cpp
index 9cac82b859..07cb7255c4 100644
--- a/src/fix_wall.cpp
+++ b/src/fix_wall.cpp
@@ -163,9 +163,6 @@ FixWall::FixWall(LAMMPS *lmp, int narg, char **arg) :
     if (xstyle[m] != EDGE) flag = 1;
 
   if (flag) {
-    if (scaleflag && domain->lattice == NULL)
-      error->all(FLERR,"Use of fix wall with undefined lattice");
-
     if (scaleflag) {
       xscale = domain->lattice->xlattice;
       yscale = domain->lattice->ylattice;
diff --git a/src/fix_wall_reflect.cpp b/src/fix_wall_reflect.cpp
index a79333ad14..9fc7d60264 100644
--- a/src/fix_wall_reflect.cpp
+++ b/src/fix_wall_reflect.cpp
@@ -115,9 +115,6 @@ FixWallReflect::FixWallReflect(LAMMPS *lmp, int narg, char **arg) :
     if (wallstyle[m] != EDGE) flag = 1;
 
   if (flag) {
-    if (scaleflag && domain->lattice == NULL)
-      error->all(FLERR,"Use of fix wall with undefined lattice");
-
     if (scaleflag) {
       xscale = domain->lattice->xlattice;
       yscale = domain->lattice->ylattice;
diff --git a/src/lattice.cpp b/src/lattice.cpp
index 5b8a5aed34..195cde8f0b 100644
--- a/src/lattice.cpp
+++ b/src/lattice.cpp
@@ -51,7 +51,9 @@ Lattice::Lattice(LAMMPS *lmp, int narg, char **arg) : Pointers(lmp)
   else error->all(FLERR,"Illegal lattice command");
 
   if (style == NONE) {
-    if (narg > 1) error->all(FLERR,"Illegal lattice command");
+    if (narg != 2) error->all(FLERR,"Illegal lattice command");
+    xlattice = ylattice = zlattice = atof(arg[1]);
+    if (xlattice <= 0.0) error->all(FLERR,"Illegal lattice command");
     return;
   }
 
diff --git a/src/region.cpp b/src/region.cpp
index 53e05a156c..a6b5022ca8 100644
--- a/src/region.cpp
+++ b/src/region.cpp
@@ -368,9 +368,6 @@ void Region::options(int narg, char **arg)
 
   // setup scaling
 
-  if (scaleflag && domain->lattice == NULL)
-    error->all(FLERR,"Use of region with undefined lattice");
-
   if (scaleflag) {
     xscale = domain->lattice->xlattice;
     yscale = domain->lattice->ylattice;
diff --git a/src/thermo.cpp b/src/thermo.cpp
index 7c49b6c98b..a146f3c169 100644
--- a/src/thermo.cpp
+++ b/src/thermo.cpp
@@ -741,16 +741,10 @@ void Thermo::parse_fields(char *str)
       addfield("Yz",&Thermo::compute_yz,FLOAT);
 
     } else if (strcmp(word,"xlat") == 0) {
-      if (domain->lattice == NULL)
-        error->all(FLERR,"Thermo keyword requires lattice be defined");
       addfield("Xlat",&Thermo::compute_xlat,FLOAT);
     } else if (strcmp(word,"ylat") == 0) {
-      if (domain->lattice == NULL)
-        error->all(FLERR,"Thermo keyword requires lattice be defined");
       addfield("Ylat",&Thermo::compute_ylat,FLOAT);
     } else if (strcmp(word,"zlat") == 0) {
-      if (domain->lattice == NULL)
-        error->all(FLERR,"Thermo keyword requires lattice be defined");
       addfield("Zlat",&Thermo::compute_zlat,FLOAT);
 
     } else if (strcmp(word,"pxx") == 0) {
@@ -1245,16 +1239,10 @@ int Thermo::evaluate_keyword(char *word, double *answer)
   else if (strcmp(word,"yz") == 0) compute_yz();
 
   else if (strcmp(word,"xlat") == 0) {
-    if (domain->lattice == NULL)
-      error->all(FLERR,"Thermo keyword in variable requires lattice be defined");
     compute_xlat();
   } else if (strcmp(word,"ylat") == 0) {
-    if (domain->lattice == NULL)
-      error->all(FLERR,"Thermo keyword in variable requires lattice be defined");
     compute_ylat();
   } else if (strcmp(word,"zlat") == 0) {
-    if (domain->lattice == NULL)
-      error->all(FLERR,"Thermo keyword in variable requires lattice be defined");
     compute_zlat();
 
   } else if (strcmp(word,"pxx") == 0) {
diff --git a/src/velocity.cpp b/src/velocity.cpp
index eb64b8cc90..b0c203b25d 100644
--- a/src/velocity.cpp
+++ b/src/velocity.cpp
@@ -378,20 +378,14 @@ void Velocity::set(int narg, char **arg)
   xscale = yscale = zscale = 1.0;
 
   if (xstyle && !xstr) {
-    if (scale_flag && domain->lattice == NULL)
-      error->all(FLERR,"Use of velocity with undefined lattice");
     if (scale_flag) xscale = domain->lattice->xlattice;
     vx *= xscale;
   }
   if (ystyle && !ystr) {
-    if (scale_flag && domain->lattice == NULL)
-      error->all(FLERR,"Use of velocity with undefined lattice");
     if (scale_flag) yscale = domain->lattice->ylattice;
     vy *= yscale;
   }
   if (zstyle && !zstr) {
-    if (scale_flag && domain->lattice == NULL)
-      error->all(FLERR,"Use of velocity with undefined lattice");
     if (scale_flag) zscale = domain->lattice->zlattice;
     vz *= zscale;
   }
@@ -552,9 +546,6 @@ void Velocity::ramp(int narg, char **arg)
 {
   // set scale factors
 
-  if (scale_flag && domain->lattice == NULL)
-    error->all(FLERR,"Use of velocity with undefined lattice");
-
   if (scale_flag) {
     xscale = domain->lattice->xlattice;
     yscale = domain->lattice->ylattice;