diff --git a/src/Makefile b/src/Makefile
index 377f4affaa..2586f541cd 100755
--- a/src/Makefile
+++ b/src/Makefile
@@ -51,7 +51,7 @@ package:
 
 yes-all:
 	make yes-class2 yes-dpd yes-granular yes-kspace \
-	yes-manybody yes-molecule yes-poems yes-xtc
+	yes-manybody yes-meam yes-molecule yes-poems yes-xtc
 
 no-all:
 	@echo 'Removing files, ignore any rm errors ...'
@@ -60,6 +60,7 @@ no-all:
 	@cd GRANULAR; csh -f Install.csh 0
 	@cd KSPACE; csh -f Install.csh 0
 	@cd MANYBODY; csh -f Install.csh 0
+	@cd MEAM; csh -f Install.csh 0
 	@cd MOLECULE; csh -f Install.csh 0
 	@cd POEMS; csh -f Install.csh 0
 	@cd XTC; csh -f Install.csh 0
@@ -100,6 +101,13 @@ no-manybody:
 	@cd MANYBODY; csh -f Install.csh 0
 	@make clean
 
+yes-meam:
+	@cd MEAM; csh -f Install.csh 1
+no-meam:
+	@echo 'Removing files, ignore any rm errors ...'
+	@cd MEAM; csh -f Install.csh 0
+	@make clean
+
 yes-molecule:
 	@cd MOLECULE; csh -f Install.csh 1
 no-molecule:
@@ -129,6 +137,7 @@ package-update:
 	@csh -f Package.csh GRANULAR update
 	@csh -f Package.csh KSPACE update
 	@csh -f Package.csh MANYBODY update
+	@csh -f Package.csh MEAM update
 	@csh -f Package.csh MOLECULE update
 	@csh -f Package.csh POEMS update
 	@csh -f Package.csh XTC update
@@ -141,6 +150,7 @@ package-overwrite:
 	@csh -f Package.csh GRANULAR overwrite
 	@csh -f Package.csh KSPACE overwrite
 	@csh -f Package.csh MANYBODY overwrite
+	@csh -f Package.csh MEAM overwrite
 	@csh -f Package.csh MOLECULE overwrite
 	@csh -f Package.csh POEMS overwrite
 	@csh -f Package.csh XTC overwrite
@@ -153,6 +163,7 @@ package-check:
 	@csh -f Package.csh GRANULAR check
 	@csh -f Package.csh KSPACE check
 	@csh -f Package.csh MANYBODY check
+	@csh -f Package.csh MEAM check
 	@csh -f Package.csh MOLECULE check
 	@csh -f Package.csh POEMS check
 	@csh -f Package.csh XTC check
diff --git a/src/create_atoms.cpp b/src/create_atoms.cpp
index 584c4cb1f2..489b6be41b 100644
--- a/src/create_atoms.cpp
+++ b/src/create_atoms.cpp
@@ -17,22 +17,13 @@
 #include "create_atoms.h"
 #include "atom.h"
 #include "comm.h"
-#include "force.h"
 #include "domain.h"
-#include "update.h"
+#include "lattice.h"
 #include "region.h"
 #include "error.h"
 
-#define SC  1
-#define BCC 2
-#define FCC 3
-#define SQ  4
-#define SQ2 5
-#define HEX 6
-#define DIAMOND 7
-
-#define MINATOMS 1000
 #define MAXATOMS 0x7FFFFFFF
+#define BIG      1.0e30
 #define EPSILON  1.0e-6
 
 /* ---------------------------------------------------------------------- */
@@ -41,30 +32,47 @@ void CreateAtoms::command(int narg, char **arg)
 {
   if (domain->box_exist == 0) 
     error->all("Create_atoms command before simulation box is defined");
-
-  if (narg != 1 && narg != 2) error->all("Illegal create_atoms command");
-
-  create_type = atoi(arg[0]);
-  if (create_type > atom->ntypes) 
-    error->all("Too large an atom type in create_atoms command");
-
-  if (strcmp(domain->lattice_style,"none") == 0)
+  if (domain->lattice == NULL)
     error->all("Cannot create atoms with undefined lattice");
-  if (!domain->orthogonality()) error->all("Non-orthogonal lattice vectors");
-  if (!domain->right_handed())
-    error->all("Orientation vectors are not right-handed");
 
-  // iregion = specified region (-1 if not specified)
+  // parse arguments
 
-  iregion = -1;
-  if (narg == 2) {
-    for (iregion = 0; iregion < domain->nregion; iregion++)
-      if (strcmp(arg[1],domain->regions[iregion]->id) == 0) break;
-    if (iregion == domain->nregion)
-      error->all("Create_atoms region ID does not exist");
+  int nbasis = domain->lattice->nbasis;
+  int basistype[nbasis];
+
+  if (narg < 1) error->all("Illegal create_atoms command");
+  int itype = atoi(arg[0]);
+  if (itype <= 0 || itype > atom->ntypes) 
+    error->all("Invalid atom type in create_atoms command");
+  for (int i = 0; i < nbasis; i++) basistype[i] = itype;
+
+  regionflag = -1;
+
+  int iarg = 1;
+  while (iarg < narg) {
+    if (strcmp(arg[iarg],"region") == 0) {
+      if (iarg+2 > narg) error->all("Illegal create_atoms command");
+      int iregion;
+      for (iregion = 0; iregion < domain->nregion; iregion++)
+	if (strcmp(arg[iarg+1],domain->regions[iregion]->id) == 0) break;
+      if (iregion == domain->nregion)
+	error->all("Create_atoms region ID does not exist");
+      regionflag = iregion;
+      iarg += 2;
+    } else if (strcmp(arg[iarg],"basis") == 0) {
+      if (iarg+3 > narg) error->all("Illegal create_atoms command");
+      int ibasis = atoi(arg[iarg+1]);
+      itype = atoi(arg[iarg+2]);
+      if (ibasis <= 0 || ibasis > nbasis || 
+	  itype <= 0 || itype > atom->ntypes) 
+	error->all("Illegal create_atoms command");
+      basistype[ibasis-1] = itype;
+      iarg += 3;
+    } else error->all("Illegal create_atoms command");
   }
 
-  // local copies of domain properties
+  // convert 8 corners of my sub-box from box coords to lattice coords
+  // min to max = bounding box around the pts in lattice space
 
   subxlo = domain->subxlo;
   subxhi = domain->subxhi;
@@ -73,86 +81,57 @@ void CreateAtoms::command(int narg, char **arg)
   subzlo = domain->subzlo;
   subzhi = domain->subzhi;
 
+  double xmin,ymin,zmin,xmax,ymax,zmax;
+  xmin = ymin = zmin = BIG;
+  xmax = ymax = zmax = -BIG;
+
+  domain->lattice->bbox(1,subxlo,subylo,subzlo,xmin,ymin,zmin,xmax,ymax,zmax);
+  domain->lattice->bbox(1,subxhi,subylo,subzlo,xmin,ymin,zmin,xmax,ymax,zmax);
+  domain->lattice->bbox(1,subxlo,subyhi,subzlo,xmin,ymin,zmin,xmax,ymax,zmax);
+  domain->lattice->bbox(1,subxhi,subyhi,subzlo,xmin,ymin,zmin,xmax,ymax,zmax);
+  domain->lattice->bbox(1,subxlo,subylo,subzhi,xmin,ymin,zmin,xmax,ymax,zmax);
+  domain->lattice->bbox(1,subxhi,subylo,subzhi,xmin,ymin,zmin,xmax,ymax,zmax);
+  domain->lattice->bbox(1,subxlo,subyhi,subzhi,xmin,ymin,zmin,xmax,ymax,zmax);
+  domain->lattice->bbox(1,subxhi,subyhi,subzhi,xmin,ymin,zmin,xmax,ymax,zmax);
+
+  // ilo:ihi,jlo:jhi,klo:khi = loop bounds for lattice overlap of my sub-box
+  // overlap = any part of a unit cell (face,edge,pt) in common with my sub-box
+  // in lattice space, sub-box is a tilted box
+  // but bbox of sub-box is aligned with lattice axes
+  // so ilo:khi unit cells should completely tile bounding box
+  // decrement lo values if min < 0, since static_cast(-1.5) = -1
+
+  int ilo,ihi,jlo,jhi,klo,khi;
+  ilo = static_cast<int> (xmin);
+  jlo = static_cast<int> (ymin);
+  klo = static_cast<int> (zmin);
+  ihi = static_cast<int> (xmax);
+  jhi = static_cast<int> (ymax);
+  khi = static_cast<int> (zmax);
+
+  if (xmin < 0.0) ilo--;
+  if (ymin < 0.0) jlo--;
+  if (zmin < 0.0) klo--;
+
+  // iterate on 3d periodic lattice using loop bounds
+  // invoke add_atom for nbasis atoms in each unit cell
+  // add_atom converts lattice coords to box coords, checks if in my sub-box
+
   boxxhi = domain->boxxhi;
   boxyhi = domain->boxyhi;
   boxzhi = domain->boxzhi;
 
-  // ilo:ihi,jlo:jhi,klo:khi = loop bounds of simple cubic lattice
-  //   that entirely overlaps my proc's sub-box
-
-  int ilo,ihi,jlo,jhi,klo,khi;
-
-  loop_bounds(0,&ilo,&ihi);
-  loop_bounds(1,&jlo,&jhi);
-  loop_bounds(2,&klo,&khi);
-
-  // initialize 3d periodic lattice using overlapping loop bounds
-  // lattice style determines how many atoms in cubic unit cell
-  // sc = 1, bcc = 2, fcc = 4, sq = 1, sq2 = 2, hex = 2, diamond = 8
-
   double natoms_previous = atom->natoms;
   int nlocal_previous = atom->nlocal;
 
-  int style;
-  if (strcmp(domain->lattice_style,"sc") == 0) style = SC;
-  else if (strcmp(domain->lattice_style,"bcc") == 0) style = BCC;
-  else if (strcmp(domain->lattice_style,"fcc") == 0) style = FCC;
-  else if (strcmp(domain->lattice_style,"sq") == 0) style = SQ;
-  else if (strcmp(domain->lattice_style,"sq2") == 0) style = SQ2;
-  else if (strcmp(domain->lattice_style,"hex") == 0) style = HEX;
-  else if (strcmp(domain->lattice_style,"diamond") == 0) style = DIAMOND;
+  double **basis = domain->lattice->basis;
 
-  double ifull,ihalf,jfull,jhalf,kfull,khalf;
-  double iquart,i3quart,jquart,j3quart,kquart,k3quart;
-  int i,j,k;
-
-  for (k = klo; k <= khi; k++) {
-    kfull = (double) k;
-    khalf = k + 0.5;
-    kquart = k + 0.25;
-    k3quart = k + 0.75;
-    for (j = jlo; j <= jhi; j++) {
-      jfull = (double) j;
-      jhalf = j + 0.5;
-      jquart = j + 0.25;
-      j3quart = j + 0.75;
-      for (i = ilo; i <= ihi; i++) {
-	ifull = (double) i;
-	ihalf = i + 0.5;
-	iquart = i + 0.25;
-	i3quart = i + 0.75;
-
-	if (style == SC)
-	  add_atom(ifull,jfull,kfull);
-	else if (style == BCC) {
-	  add_atom(ifull,jfull,kfull);
-	  add_atom(ihalf,jhalf,khalf);
-	} else if (style == FCC) {
-	  add_atom(ifull,jfull,kfull);
-	  add_atom(ihalf,jhalf,kfull);
-	  add_atom(ihalf,jfull,khalf);
-	  add_atom(ifull,jhalf,khalf);
-	} else if (style == SQ) {
-	  add_atom(ifull,jfull,kfull);
-	} else if (style == SQ2) {
-	  add_atom(ifull,jfull,kfull);
-	  add_atom(ihalf,jhalf,kfull);
-	} else if (style == HEX) {
-	  add_atom(ifull,jfull,kfull);
-	  add_atom(ihalf,jhalf,kfull);
-	} else if (style == DIAMOND) {
-	  add_atom(ifull,jfull,kfull);
-	  add_atom(ifull,jhalf,khalf);
-	  add_atom(ihalf,jfull,khalf);
-	  add_atom(ihalf,jhalf,kfull);
-	  add_atom(iquart,jquart,kquart);
-	  add_atom(iquart,j3quart,k3quart);
-	  add_atom(i3quart,jquart,k3quart);
-	  add_atom(i3quart,j3quart,kquart);
-	}
-      }
-    }
-  }
+  int i,j,k,m;
+  for (k = klo; k <= khi; k++)
+    for (j = jlo; j <= jhi; j++)
+      for (i = ilo; i <= ihi; i++)
+	for (m = 0; m < nbasis; m++)
+	  add_atom(basistype[m],i+basis[m][0],j+basis[m][1],k+basis[m][2]);
 
   // new total # of atoms
 
@@ -191,19 +170,19 @@ void CreateAtoms::command(int narg, char **arg)
 }
 
 /* ----------------------------------------------------------------------
-   add an atom at x,y,z in lattice coords if it meets all criteria 
+   add an atom of type at lattice coords x,y,z if it meets all criteria 
 ------------------------------------------------------------------------- */
 
-void CreateAtoms::add_atom(double x, double y, double z)
+void CreateAtoms::add_atom(int type, double x, double y, double z)
 {
   // convert from lattice coords to box coords
 
-  domain->lattice2box(&x,&y,&z);
+  domain->lattice->lattice2box(x,y,z);
 
   // if a region was specified, test if atom is in it
 
-  if (iregion >= 0)
-    if (!domain->regions[iregion]->match(x,y,z)) return;
+  if (regionflag >= 0)
+    if (!domain->regions[regionflag]->match(x,y,z)) return;
 
   // test if atom is in my subbox
 
@@ -220,120 +199,5 @@ void CreateAtoms::add_atom(double x, double y, double z)
 
   // add the atom to my list of atoms
 
-  atom->create_one(create_type,x,y,z);
-}
-
-/* ----------------------------------------------------------------------
-   search for 2 bounding lattice planes that completely enclose my sub-box
-   do this by testing if all corner points of my sub-box lie on correct side
-     of a lattice plane via same_side function
-   dim = 0,1,2 for x,y,z directions
-   lo,hi = returned indices of 2 bounding lattice planes
-   a lattice plane is defined by:
-     point = point in lattice space through which the plane passes
-     normal = vector normal to lattice plane
-------------------------------------------------------------------------- */
-
-void CreateAtoms::loop_bounds(int dim, int *lo, int *hi)
-{
-  int normal[3],point[3];
-
-  // start search at origin
-
-  point[0] = point[1] = point[2] = 0;
-
-  // set lattice plane direction along positive lattice axis
-
-  normal[0] = normal[1] = normal[2] = 0;
-  normal[dim] = 1;
-
-  // step down (if needed) until entire box is above the plane
-  // step up until 1st time entire box is not above the plane
-
-  while (!same_side(point,normal)) point[dim]--;
-  while (same_side(point,normal)) point[dim]++;
-
-  // lower loop bound = current loc minus 1 (subtract 1 more for safety)
-
-  *lo = point[dim] - 2;
-
-  // flip plane direction
-  // step up until entire box is below the plane
-
-  normal[dim] = -1;
-  while (!same_side(point,normal)) point[dim]++;
-
-  // lower loop bound = current loc (add 1 more for safety)
-
-  *hi = point[dim] + 1;
-}
-
-/* ----------------------------------------------------------------------
-   test if all 8 corner points of my sub-box are on "correct" side of a plane
-   plane is defined by point[3] it goes thru and a normal[3]
-   normal also defines the correct side 
-------------------------------------------------------------------------- */
-
-int CreateAtoms::same_side(int *point, int *normal)
-{
-  // p1 = plane center point in box coords
-  // p2 = point on correct side of plane, in box coords
-
-  double p1x = point[0];
-  double p1y = point[1];
-  double p1z = point[2];
-  domain->lattice2box(&p1x,&p1y,&p1z);
-
-  double p2x = point[0] + normal[0];
-  double p2y = point[1] + normal[1];
-  double p2z = point[2] + normal[2];
-  domain->lattice2box(&p2x,&p2y,&p2z);
-
-  // for each of 8 sub-box corner points, dot these 2 vectors:
-  //   v1 = from plane center point to point on correct side of plane
-  //   v2 = from plane center point to box corner point
-  // negative result = portion of box is on wrong side of plane, return 0
-
-  double v1[3],v2[3];
-
-  points2vec(p1x,p1y,p1z,p2x,p2y,p2z,v1);
-
-  points2vec(p1x,p1y,p1z,subxlo,subylo,subzlo,v2);
-  if (dot(v1,v2) < 0.0) return 0;
-  points2vec(p1x,p1y,p1z,subxhi,subylo,subzlo,v2);
-  if (dot(v1,v2) < 0.0) return 0;
-  points2vec(p1x,p1y,p1z,subxlo,subyhi,subzlo,v2);
-  if (dot(v1,v2) < 0.0) return 0;
-  points2vec(p1x,p1y,p1z,subxhi,subyhi,subzlo,v2);
-  if (dot(v1,v2) < 0.0) return 0;
-  points2vec(p1x,p1y,p1z,subxlo,subylo,subzhi,v2);
-  if (dot(v1,v2) < 0.0) return 0;
-  points2vec(p1x,p1y,p1z,subxhi,subylo,subzhi,v2);
-  if (dot(v1,v2) < 0.0) return 0;
-  points2vec(p1x,p1y,p1z,subxlo,subyhi,subzhi,v2);
-  if (dot(v1,v2) < 0.0) return 0;
-  points2vec(p1x,p1y,p1z,subxhi,subyhi,subzhi,v2);
-  if (dot(v1,v2) < 0.0) return 0;
-
-  // all 8 points were on correct side
-
-  return 1;
-}
-
-/* ---------------------------------------------------------------------- */
-				 
-double CreateAtoms::dot(double *vec1, double *vec2)
-{
-  double sum = vec1[0]*vec2[0] + vec1[1]*vec2[1] + vec1[2]*vec2[2];
-  return sum;
-}
-
-/* ---------------------------------------------------------------------- */
-
-void CreateAtoms::points2vec(double p1x, double p1y, double p1z,
-			     double p2x, double p2y, double p2z, double *v)
-{
-  v[0] = p2x - p1x;
-  v[1] = p2y - p1y;
-  v[2] = p2z - p1z;
+  atom->create_one(type,x,y,z);
 }
diff --git a/src/create_atoms.h b/src/create_atoms.h
index 57d1541e87..7b9e7ceba4 100644
--- a/src/create_atoms.h
+++ b/src/create_atoms.h
@@ -23,16 +23,11 @@ class CreateAtoms : public LAMMPS {
   void command(int, char **);
 
  private:
-  int create_type;
-  double subxlo,subxhi,subylo,subyhi,subzlo,subzhi;
+  int regionflag;
   double boxxhi,boxyhi,boxzhi;
-  int iregion;
+  double subxlo,subxhi,subylo,subyhi,subzlo,subzhi;
 
-  void add_atom(double, double, double);
-  void loop_bounds(int, int *, int *);
-  int same_side(int *, int *);
-  double dot(double *, double *);
-  void points2vec(double, double, double, double, double, double, double *);
+  void add_atom(int, double, double, double);
 };
 
 #endif
diff --git a/src/displace_atoms.cpp b/src/displace_atoms.cpp
index 803ff5cae0..2f73bdc46e 100644
--- a/src/displace_atoms.cpp
+++ b/src/displace_atoms.cpp
@@ -18,6 +18,7 @@
 #include "system.h"
 #include "atom.h"
 #include "domain.h"
+#include "lattice.h"
 #include "comm.h"
 #include "group.h"
 #include "error.h"
@@ -67,14 +68,14 @@ void DisplaceAtoms::command(int narg, char **arg)
 
   // setup scaling
 
-  if (scaleflag && strcmp(domain->lattice_style,"none") == 0)
+  if (scaleflag && domain->lattice == NULL)
     error->all("Use of displace_atoms with undefined lattice");
 
   double xscale,yscale,zscale;
   if (scaleflag) {
-    xscale = domain->xlattice;
-    yscale = domain->ylattice;
-    zscale = domain->zlattice;
+    xscale = domain->lattice->xlattice;
+    yscale = domain->lattice->ylattice;
+    zscale = domain->lattice->zlattice;
   }
   else xscale = yscale = zscale = 1.0;
 
diff --git a/src/domain.cpp b/src/domain.cpp
index b379a4a549..32c7993337 100644
--- a/src/domain.cpp
+++ b/src/domain.cpp
@@ -23,6 +23,7 @@
 #include "modify.h"
 #include "fix.h"
 #include "region.h"
+#include "lattice.h"
 #include "comm.h"
 #include "memory.h"
 #include "error.h"
@@ -47,6 +48,10 @@ Domain::Domain()
 
   nonperiodic = 0;
   xperiodic = yperiodic = zperiodic = 1;
+  periodicity[0] = xperiodic;
+  periodicity[1] = yperiodic;
+  periodicity[2] = zperiodic;
+
   boundary[0][0] = boundary[0][1] = 0;
   boundary[1][0] = boundary[1][1] = 0;
   boundary[2][0] = boundary[2][1] = 0;
@@ -54,16 +59,7 @@ Domain::Domain()
   boxxlo = boxylo = boxzlo = -0.5;
   boxxhi = boxyhi = boxzhi = 0.5;
 
-  char *str = "none";
-  int n = strlen(str) + 1;
-  lattice_style = new char[n];
-  strcpy(lattice_style,str);
-
-  origin_x = origin_y = origin_z = 0.0;
-  orient_x[0] = 1; orient_x[1] = 0; orient_x[2] = 0;
-  orient_y[0] = 0; orient_y[1] = 1; orient_y[2] = 0;
-  orient_z[0] = 0; orient_z[1] = 0; orient_z[2] = 1;
-
+  lattice = NULL;
   nregion = maxregion = 0;
   regions = NULL;
 }
@@ -72,7 +68,7 @@ Domain::Domain()
 
 Domain::~Domain()
 {
-  delete [] lattice_style;
+  delete lattice;
   for (int i = 0; i < nregion; i++) delete regions[i];
   memory->sfree(regions);
 }
@@ -95,9 +91,8 @@ void Domain::init()
 }
 
 /* ----------------------------------------------------------------------
-   setup initial global box, boxxlo-boxzhi are already set
-   adjust for any shrink-wrapped boundaries
-   store min values if boundary type = 3 = "m"
+   set initial global box from boxlo/hi (already set by caller)
+   adjust for shrink-wrapped dims
 ------------------------------------------------------------------------- */
 
 void Domain::set_initial_box()
@@ -119,8 +114,7 @@ void Domain::set_initial_box()
 }
 
 /* ----------------------------------------------------------------------
-   setup global box parameters
-   set prd, prd_half, prd[], boxlo/hi[], periodicity[]
+   set global prd, prd_half, prd[], boxlo/hi[] from boxlo/hi
 ------------------------------------------------------------------------- */
 
 void Domain::set_global_box()
@@ -136,14 +130,10 @@ void Domain::set_global_box()
   prd[0]   = xprd;    prd[1]   = yprd;    prd[2]   = zprd;
   boxlo[0] = boxxlo;  boxlo[1] = boxylo;  boxlo[2] = boxzlo;
   boxhi[0] = boxxhi;  boxhi[1] = boxyhi;  boxhi[2] = boxzhi;
-  periodicity[0] = xperiodic;
-  periodicity[1] = yperiodic;
-  periodicity[2] = zperiodic;
 }
 
 /* ----------------------------------------------------------------------
-   set local subbox from global boxxlo-boxzhi and proc grid
-   set subxlo-subzhi, sublo/hi[] 
+   set local subxlo-subzhi, sublo/hi[] from global boxxlo-boxzhi and proc grid
    for uppermost proc, insure subhi = boxhi (in case round-off occurs)
 ------------------------------------------------------------------------- */
 
@@ -170,8 +160,8 @@ void Domain::set_local_box()
 
 /* ----------------------------------------------------------------------
    reset global & local boxes due to global box boundary changes
-   if shrink-wrapped, determine atom extent and reset boxxlo thru boxzhi
-   call set_global_box and set_local_box 
+   if shrink-wrapped, determine atom extent and reset boxlo/hi
+   set global & local boxes from new boxlo/hi values
 ------------------------------------------------------------------------- */
 
 void Domain::reset_box()
@@ -199,7 +189,6 @@ void Domain::reset_box()
 
     // compute extent across all procs
     // flip sign of MIN to do it in one Allreduce MAX
-    // set box by extent in shrink-wrapped dims
 
     extent[0][0] = -extent[0][0];
     extent[1][0] = -extent[1][0];
@@ -207,8 +196,7 @@ void Domain::reset_box()
 
     MPI_Allreduce(extent,all,6,MPI_DOUBLE,MPI_MAX,world);
 
-    // if any of 6 dims is shrink-wrapped, set it to extent of atoms +/- SMALL
-    // enforce min extent for boundary type = 3 = "m"
+    // in shrink-wrapped dims, set box by atom extent
     
     if (xperiodic == 0) {
       if (boundary[0][0] == 2) boxxlo = -all[0][0] - SMALL;
@@ -460,151 +448,18 @@ void Domain::unmap(double &x, double &y, double &z, int image)
 }
 
 /* ----------------------------------------------------------------------
-   set lattice constant 
+   create a lattice
+   delete it if style = none
 ------------------------------------------------------------------------- */
 
 void Domain::set_lattice(int narg, char **arg)
 {
-  if (narg < 1) error->all("Illegal lattice command");
-
-  delete [] lattice_style;
-  int n = strlen(arg[0]) + 1;
-  lattice_style = new char[n];
-  strcpy(lattice_style,arg[0]);
-
-  if (strcmp(arg[0],"none") == 0) return;
-
-  if (narg != 2) error->all("Illegal lattice command");
-
-  if (strcmp(arg[0],"sc") && strcmp(arg[0],"bcc") && strcmp(arg[0],"fcc") &&
-      strcmp(arg[0],"sq") && strcmp(arg[0],"sq2") && strcmp(arg[0],"hex") &&
-      strcmp(arg[0],"diamond"))
-    error->all("Illegal lattice command");
-
-  // check that lattice matches dimension
-
-  int dim = force->dimension;
-
-  if (dim == 2) {
-    if (strcmp(arg[0],"sq") && strcmp(arg[0],"sq2") && strcmp(arg[0],"hex"))
-      error->all("Lattice style incompatible with dimension");
+  delete lattice;
+  lattice = new Lattice(narg,arg);
+  if (lattice->style == 0) {
+    delete lattice;
+    lattice = NULL;
   }
-
-  if (dim == 3) {
-    if (strcmp(arg[0],"sc") && strcmp(arg[0],"bcc") &&
-	strcmp(arg[0],"fcc") && strcmp(arg[0],"diamond"))
-      error->all("Lattice style incompatible with dimension");
-  }
-
-  // set lattice constants depending on # of atoms per unit cell
-  // hex is only case where xlattice = ylattice = zlattice is not true
-
-  double value = atof(arg[1]);
-
-  if (!strcmp(arg[0],"sc") || !strcmp(arg[0],"sq")) {
-    if (strcmp(update->unit_style,"lj") == 0)
-      xlattice = ylattice = zlattice = pow(1.0/value,1.0/dim);
-    else xlattice = ylattice = zlattice = value;
-  }
-
-  if (!strcmp(arg[0],"bcc") || !strcmp(arg[0],"sq2")) {
-    if (strcmp(update->unit_style,"lj") == 0)
-      xlattice = ylattice = zlattice = pow(2.0/value,1.0/dim);
-    else xlattice = ylattice = zlattice = value;
-  }
-
-  if (strcmp(arg[0],"fcc") == 0) {
-    if (strcmp(update->unit_style,"lj") == 0)
-      xlattice = ylattice = zlattice = pow(4.0/value,1.0/dim);
-    else xlattice = ylattice = zlattice = value;
-  }
-
-  if (strcmp(arg[0],"hex") == 0) {
-    if (strcmp(update->unit_style,"lj") == 0)
-      xlattice = zlattice = pow(2.0/sqrt(3.0)/value,1.0/dim);
-    else xlattice = zlattice = value;
-    ylattice = xlattice * sqrt(3.0);
-  }
-
-  if (strcmp(arg[0],"diamond") == 0) {
-    if (strcmp(update->unit_style,"lj") == 0)
-      xlattice = ylattice = zlattice = pow(8.0/value,1.0/dim);
-    else xlattice = ylattice = zlattice = value;
-  }
-}
-
-/* ----------------------------------------------------------------------
-   check if orientation vectors are mutually orthogonal 
-------------------------------------------------------------------------- */
-
-int Domain::orthogonality()
-{
-  if (orient_x[0]*orient_y[0] + orient_x[1]*orient_y[1] + 
-      orient_x[2]*orient_y[2]) return 0;
-
-  if (orient_y[0]*orient_z[0] + orient_y[1]*orient_z[1] + 
-      orient_y[2]*orient_z[2]) return 0;
-
-  if (orient_x[0]*orient_z[0] + orient_x[1]*orient_z[1] + 
-      orient_x[2]*orient_z[2]) return 0;
-
-  return 1;
-}
-
-/* ----------------------------------------------------------------------
-   check righthandedness of orientation vectors
-   x cross y must be in same direction as z 
-------------------------------------------------------------------------- */
-
-int Domain::right_handed()
-{
-  int xy0 = orient_x[1]*orient_y[2] - orient_x[2]*orient_y[1];
-  int xy1 = orient_x[2]*orient_y[0] - orient_x[0]*orient_y[2];
-  int xy2 = orient_x[0]*orient_y[1] - orient_x[1]*orient_y[0];
-  if (xy0*orient_z[0] + xy1*orient_z[1] + xy2*orient_z[2] <= 0) return 0;
-  return 1;
-}
-
-/* ----------------------------------------------------------------------
-   convert lattice coords into box coords
-   x,y,z = point in lattice coords
-   orient_xyz = lattice vectors that point in positive x,y,z box directions
-   origin_xyz = origin of lattice in lattice units
-   return xnew,ynew,znew = point in box coords
-   method:
-     compute projection of vector from (0,0,0) to lattice onto each
-       orient vector via dot product scaled by length of
-       orient vector in lattice coords
-     this projection (offset by origin and scaled by lattice constant)
-       gives x,y,z box coords 
-------------------------------------------------------------------------- */
-
-void Domain::lattice2box(double *x, double *y, double *z)
-{
-  double length;
-  double dotprod;
-
-  length = orient_x[0]*orient_x[0] + orient_x[1]*orient_x[1] +
-    orient_x[2]*orient_x[2];
-  length = sqrt(length);
-  dotprod = *x * orient_x[0] + *y * orient_x[1] + *z * orient_x[2];
-  double xnew = (dotprod/length + origin_x) * xlattice;
-
-  length = orient_y[0]*orient_y[0] + orient_y[1]*orient_y[1] +
-    orient_y[2]*orient_y[2];
-  length = sqrt(length);
-  dotprod = *x * orient_y[0] + *y * orient_y[1] + *z * orient_y[2];
-  double ynew = (dotprod/length + origin_y) * ylattice;
-
-  length = orient_z[0]*orient_z[0] + orient_z[1]*orient_z[1] +
-     orient_z[2]*orient_z[2];
-  length = sqrt(length);
-  dotprod = *x * orient_z[0] + *y * orient_z[1] + *z * orient_z[2];
-  double znew = (dotprod/length + origin_z) * zlattice;
-
-  *x = xnew;
-  *y = ynew;
-  *z = znew;
 }
 
 /* ----------------------------------------------------------------------
@@ -678,6 +533,10 @@ void Domain::set_boundary(int narg, char **arg)
   if (boundary[2][0] == 0) zperiodic = 1;
   else zperiodic = 0;
 
+  periodicity[0] = xperiodic;
+  periodicity[1] = yperiodic;
+  periodicity[2] = zperiodic;
+
   nonperiodic = 0;
   if (xperiodic == 0 || yperiodic == 0 || zperiodic == 0) {
     nonperiodic = 1;
diff --git a/src/domain.h b/src/domain.h
index 38c70ecc2d..31cddeb8cc 100644
--- a/src/domain.h
+++ b/src/domain.h
@@ -15,6 +15,7 @@
 #define DOMAIN_H
 
 #include "lammps.h"
+class Lattice;
 class Region;
 
 class Domain : public LAMMPS {
@@ -32,7 +33,7 @@ class Domain : public LAMMPS {
                                             // 3 = shrink-wrap non-per w/ min
 
   double minxlo,minxhi;                     // minimum size of global box
-  double minylo,minyhi;                     //   when shrink-wrapping
+  double minylo,minyhi;                     // when shrink-wrapping
   double minzlo,minzhi;
 
   double boxxlo,boxxhi;                     // global box boundaries 
@@ -40,6 +41,7 @@ class Domain : public LAMMPS {
   double boxzlo,boxzhi;
 
   double xprd,yprd,zprd;                    // global box size
+  double xprd_half,yprd_half,zprd_half;
 
   double subxlo,subxhi;                     // sub-box boudaries on this proc
   double subylo,subyhi;
@@ -50,19 +52,9 @@ class Domain : public LAMMPS {
   double sublo[3],subhi[3];                 // sub-box bounds as arrays
   int periodicity[3];                       // xyz periodic as array
 
-  double xprd_half,yprd_half,zprd_half;
-
   int box_change;            // 1 if box bounds ever change, 0 if fixed
 
-                                       // params for create_atoms command
-  char *lattice_style;                 // lattice: none
-                                       // 3d = fcc, bcc, sc
-                                       // 2d = sq, sq2, hex
-  double xlattice,ylattice,zlattice;   // lattice const in 3 directions
-  double origin_x,origin_y,origin_z;   // lattice origin
-  int orient_x[3];                     // lattice vectors
-  int orient_y[3];
-  int orient_z[3];
+  Lattice *lattice;              // user-defined lattice
 
   int nregion;                   // # of defined Regions
   int maxregion;                 // max # list can hold
@@ -81,9 +73,6 @@ class Domain : public LAMMPS {
   void minimum_image(double *, double *, double *);
   void minimum_image(double *);
   void set_lattice(int, char **);
-  int orthogonality();
-  int right_handed();
-  void lattice2box(double *, double *, double *);
   void add_region(int, char **);
   void set_boundary(int, char **);
 };
diff --git a/src/fix_indent.cpp b/src/fix_indent.cpp
index ed8f9d78da..511f43cfa4 100644
--- a/src/fix_indent.cpp
+++ b/src/fix_indent.cpp
@@ -21,6 +21,7 @@
 #include "fix_indent.h"
 #include "atom.h"
 #include "domain.h"
+#include "lattice.h"
 #include "update.h"
 #include "output.h"
 #include "respa.h"
@@ -51,14 +52,14 @@ FixIndent::FixIndent(int narg, char **arg) : Fix(narg, arg)
 
   // setup scaling
 
-  if (scaleflag && strcmp(domain->lattice_style,"none") == 0)
+  if (scaleflag && domain->lattice == NULL)
     error->all("Use of fix indent with undefined lattice");
 
   double xscale,yscale,zscale;
   if (scaleflag) {
-    xscale = domain->xlattice;
-    yscale = domain->ylattice;
-    zscale = domain->zlattice;
+    xscale = domain->lattice->xlattice;
+    yscale = domain->lattice->ylattice;
+    zscale = domain->lattice->zlattice;
   }
   else xscale = yscale = zscale = 1.0;
 
diff --git a/src/fix_recenter.cpp b/src/fix_recenter.cpp
index 7627544e4b..f40324b915 100644
--- a/src/fix_recenter.cpp
+++ b/src/fix_recenter.cpp
@@ -21,6 +21,7 @@
 #include "atom.h"
 #include "group.h"
 #include "domain.h"
+#include "lattice.h"
 #include "modify.h"
 #include "comm.h"
 #include "error.h"
@@ -68,11 +69,14 @@ FixRecenter::FixRecenter(int narg, char **arg) : Fix(narg, arg)
 
   // scale xcom,ycom,zcom
 
+  if (scaleflag == 1 && domain->lattice == NULL)
+    error->all("Use of fix recenter with undefined lattice");
+
   double xscale,yscale,zscale;
   if (scaleflag == 1) {
-    xscale = domain->xlattice;
-    yscale = domain->ylattice;
-    zscale = domain->zlattice;
+    xscale = domain->lattice->xlattice;
+    yscale = domain->lattice->ylattice;
+    zscale = domain->lattice->zlattice;
   }
   else xscale = yscale = zscale = 1.0;
 
diff --git a/src/input.cpp b/src/input.cpp
index d843243c90..8e7b3dce41 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -420,8 +420,6 @@ int Input::execute_command()
   else if (!strcmp(command,"neighbor")) neighbor_command();
   else if (!strcmp(command,"newton")) newton();
   else if (!strcmp(command,"next")) next_command();
-  else if (!strcmp(command,"orient")) orient();
-  else if (!strcmp(command,"origin")) origin();
   else if (!strcmp(command,"pair_coeff")) pair_coeff();
   else if (!strcmp(command,"pair_modify")) pair_modify();
   else if (!strcmp(command,"pair_style")) pair_style();
@@ -890,43 +888,6 @@ void Input::next_command()
 
 /* ---------------------------------------------------------------------- */
 
-void Input::orient()
-{
-  if (narg != 4) error->all("Illegal orient command");
-
-  if (strcmp(arg[0],"x") == 0) {
-    domain->orient_x[0] = atoi(arg[1]);
-    domain->orient_x[1] = atoi(arg[2]);
-    domain->orient_x[2] = atoi(arg[3]);
-  } else if (strcmp(arg[0],"y") == 0) {
-    domain->orient_y[0] = atoi(arg[1]);
-    domain->orient_y[1] = atoi(arg[2]);
-    domain->orient_y[2] = atoi(arg[3]);
-  } else if (strcmp(arg[0],"z") == 0) {
-    domain->orient_z[0] = atoi(arg[1]);
-    domain->orient_z[1] = atoi(arg[2]);
-    domain->orient_z[2] = atoi(arg[3]);
-  } else error->all("Illegal orient command");
-}
-
-/* ---------------------------------------------------------------------- */
-
-void Input::origin()
-{
-  if (narg != 3) error->all("Illegal origin command");
-
-  domain->origin_x = atof(arg[0]);
-  domain->origin_y = atof(arg[1]);
-  domain->origin_z = atof(arg[2]);
-
-  if (domain->origin_x < 0.0 || domain->origin_x > 1.0 ||
-      domain->origin_y < 0.0 || domain->origin_y > 1.0 ||
-      domain->origin_x < 0.0 || domain->origin_z > 1.0)
-    error->all("Illegal origin command");
-}
-
-/* ---------------------------------------------------------------------- */
-
 void Input::pair_coeff()
 {
   if (domain->box_exist == 0)
diff --git a/src/input.h b/src/input.h
index 80077f360e..eec6ddc8c6 100644
--- a/src/input.h
+++ b/src/input.h
@@ -84,8 +84,6 @@ class Input : public LAMMPS {
   void neighbor_command();
   void newton();
   void next_command();
-  void orient();
-  void origin();
   void pair_coeff();
   void pair_modify();
   void pair_style();
diff --git a/src/region.cpp b/src/region.cpp
index 49b3c2ce4e..5aeb6b8ac2 100644
--- a/src/region.cpp
+++ b/src/region.cpp
@@ -15,6 +15,7 @@
 #include "string.h"
 #include "region.h"
 #include "domain.h"
+#include "lattice.h"
 #include "error.h"
 
 /* ---------------------------------------------------------------------- */
@@ -70,13 +71,13 @@ void Region::options(int narg, char **arg)
 
   // setup scaling
 
-  if (scaleflag && strcmp(domain->lattice_style,"none") == 0)
+  if (scaleflag && domain->lattice == NULL)
     error->all("Use of region with undefined lattice");
 
   if (scaleflag) {
-    xscale = domain->xlattice;
-    yscale = domain->ylattice;
-    zscale = domain->zlattice;
+    xscale = domain->lattice->xlattice;
+    yscale = domain->lattice->ylattice;
+    zscale = domain->lattice->zlattice;
   }
   else xscale = yscale = zscale = 1.0;
 }
diff --git a/src/temperature.cpp b/src/temperature.cpp
index ea9436deb9..86fc68fa30 100644
--- a/src/temperature.cpp
+++ b/src/temperature.cpp
@@ -19,6 +19,7 @@
 #include "group.h"
 #include "modify.h"
 #include "domain.h"
+#include "lattice.h"
 #include "fix.h"
 #include "error.h"
 
@@ -60,13 +61,13 @@ Temperature::Temperature(int narg, char **arg)
 
   if (strcmp(style,"ramp") == 0) {
 
-    if (scaleflag && strcmp(domain->lattice_style,"none") == 0)
+    if (scaleflag && domain->lattice == NULL)
       error->all("Use of temperature ramp with undefined lattice");
 
     if (scaleflag) {
-      xscale = domain->xlattice;
-      yscale = domain->ylattice;
-      zscale = domain->zlattice;
+      xscale = domain->lattice->xlattice;
+      yscale = domain->lattice->ylattice;
+      zscale = domain->lattice->zlattice;
     }
     else xscale = yscale = zscale = 1.0;
   }
diff --git a/src/velocity.cpp b/src/velocity.cpp
index 2fbdd7cabe..f0a04f5fd6 100644
--- a/src/velocity.cpp
+++ b/src/velocity.cpp
@@ -20,6 +20,7 @@
 #include "atom.h"
 #include "update.h"
 #include "domain.h"
+#include "lattice.h"
 #include "force.h"
 #include "temperature.h"
 #include "temp_full.h"
@@ -96,13 +97,13 @@ void Velocity::command(int narg, char **arg)
   // set scaling for SET and RAMP styles
 
   if (style == SET || style == RAMP) {
-    if (scale_flag && strcmp(domain->lattice_style,"none") == 0)
+    if (scale_flag && domain->lattice == NULL)
       error->all("Use of velocity with undefined lattice");
 
     if (scale_flag) {
-      xscale = domain->xlattice;
-      yscale = domain->ylattice;
-      zscale = domain->zlattice;
+      xscale = domain->lattice->xlattice;
+      yscale = domain->lattice->ylattice;
+      zscale = domain->lattice->zlattice;
     }
     else xscale = yscale = zscale = 1.0;
   }
@@ -582,7 +583,7 @@ void Velocity::zero_rotation()
       dy = (x[i][1] + ybox*yprd) - xcm[1];
       dz = (x[i][2] + zbox*zprd) - xcm[2];
       v[i][0] -= omega[1]*dz - omega[2]*dy;
-      v[i][1] -= omega[2]*dx - omega[0]*dz;
+      v[i][1] -= omega[2]*dx - omega[0]*dy;
       v[i][2] -= omega[0]*dy - omega[1]*dx;
     }
 }