diff -Naur lammps-7Oct08/doc/fix_wall_lj126.html lammps-8Oct08/doc/fix_wall_lj126.html --- lammps-7Oct08/doc/fix_wall_lj126.html 2008-10-01 10:07:42.000000000 -0600 +++ lammps-8Oct08/doc/fix_wall_lj126.html 2008-10-06 08:33:34.000000000 -0600 @@ -13,19 +13,35 @@
Syntax:
fix ID group-ID wall/lj126 style coord epsilon sigma cutoff 
+fix ID group-ID wall/lj126 style coord epsilon sigma cutoff keyword values ... 
 
-ID, group-ID are documented in fix command
-
wall/lj126 = style name of this fix command
-
style = xlo or xhi or ylo or yhi or zlo or zhi
-
coord = position of wall
-
epsilon = Lennard-Jones epsilon for wall-particle interaction
-
sigma = Lennard-Jones sigma for wall-particle interaction
-
cutoff = distance from wall at which wall-particle interaction is cut off 
+ID, group-ID are documented in fix command 
+
+
wall/lj126 = style name of this fix command 
+
+
style = xlo or xhi or ylo or yhi or zlo or zhi 
+
+
coord = position of wall 
+
+
epsilon = Lennard-Jones epsilon for wall-particle interaction 
+
+
sigma = Lennard-Jones sigma for wall-particle interaction 
+
+
cutoff = distance from wall at which wall-particle interaction is cut off (distance units) 
+
+
one or more keyword/value pairs may be appended 
+
+
keyword = vel 
+
+  vel args = v
+    v = velocity of wall in perpendicular direction (velocity units) 
+
+
 
 Examples:
 
-fix wallhi all wall/lj126 xhi 10.0 1.0 1.0 1.12 
+fix wallhi all wall/lj126 xhi 10.0 1.0 1.0 1.12
+fix leftwall all wall/lj126 zlo 0.0  1.0 1.0 0.858 vel 1.0 
 
 Description:
 
@@ -44,6 +60,14 @@
 The wall potential is shifted so that the energy of a wall-particle
 interaction is 0.0 at the cutoff distance.
 
+If the vel keyword is specified, the position of wall will move
+during the simulation, based on its initial position (coord) and the
+specified velocity (vel).  Xlo or xhi walls move in the x
+direction with whatever sign you give the v argument.  Ditto for y
+and z walls.  Note that if you do multiple runs, the initial
+position of the wall does not change, so it will continue to move at
+the specified velocity.
+
 Restart, fix_modify, output, run start/stop, minimize info:
 
 No information about this fix is written to binary restart
@@ -80,6 +104,8 @@
 
fix wall/reflect, fix
 wall/lj93
 
-Default: none
+
Default:
+
+The option defaults are vel = 0.
 
 
diff -Naur lammps-7Oct08/doc/fix_wall_lj126.txt lammps-8Oct08/doc/fix_wall_lj126.txt
--- lammps-7Oct08/doc/fix_wall_lj126.txt	2008-10-01 10:07:35.000000000 -0600
+++ lammps-8Oct08/doc/fix_wall_lj126.txt	2008-10-06 08:33:34.000000000 -0600
@@ -10,19 +10,25 @@
 
 [Syntax:]
 
-fix ID group-ID wall/lj126 style coord epsilon sigma cutoff :pre
+fix ID group-ID wall/lj126 style coord epsilon sigma cutoff keyword values ... :pre
 
-ID, group-ID are documented in "fix"_fix.html command
-wall/lj126 = style name of this fix command
-style = {xlo} or {xhi} or {ylo} or {yhi} or {zlo} or {zhi}
-coord = position of wall
-epsilon = Lennard-Jones epsilon for wall-particle interaction
-sigma = Lennard-Jones sigma for wall-particle interaction
-cutoff = distance from wall at which wall-particle interaction is cut off :ul
+ID, group-ID are documented in "fix"_fix.html command :ulb,l
+wall/lj126 = style name of this fix command :l
+style = {xlo} or {xhi} or {ylo} or {yhi} or {zlo} or {zhi} :l
+coord = position of wall :l
+epsilon = Lennard-Jones epsilon for wall-particle interaction :l
+sigma = Lennard-Jones sigma for wall-particle interaction :l
+cutoff = distance from wall at which wall-particle interaction is cut off (distance units) :l
+one or more keyword/value pairs may be appended :l
+keyword = {vel} :l
+  {vel} args = v
+    v = velocity of wall in perpendicular direction (velocity units) :pre
+:ule
 
 [Examples:]
 
-fix wallhi all wall/lj126 xhi 10.0 1.0 1.0 1.12 :pre
+fix wallhi all wall/lj126 xhi 10.0 1.0 1.0 1.12
+fix leftwall all wall/lj126 zlo 0.0  1.0 1.0 0.858 vel 1.0 :pre
 
 [Description:]
 
@@ -41,6 +47,14 @@
 The wall potential is shifted so that the energy of a wall-particle
 interaction is 0.0 at the cutoff distance.
 
+If the {vel} keyword is specified, the position of wall will move
+during the simulation, based on its initial position (coord) and the
+specified velocity (vel).  {Xlo} or {xhi} walls move in the x
+direction with whatever sign you give the {v} argument.  Ditto for {y}
+and {z} walls.  Note that if you do multiple runs, the initial
+position of the wall does not change, so it will continue to move at
+the specified velocity.
+
 [Restart, fix_modify, output, run start/stop, minimize info:]
 
 No information about this fix is written to "binary restart
@@ -77,4 +91,6 @@
 "fix wall/reflect"_fix_wall_reflect.html, "fix
 wall/lj93"_fix_wall_lj93.html
 
-[Default:] none
+[Default:]
+
+The option defaults are vel = 0.
diff -Naur lammps-7Oct08/doc/fix_wall_lj93.html lammps-8Oct08/doc/fix_wall_lj93.html
--- lammps-7Oct08/doc/fix_wall_lj93.html	2008-10-01 10:07:42.000000000 -0600
+++ lammps-8Oct08/doc/fix_wall_lj93.html	2008-10-06 08:33:34.000000000 -0600
@@ -13,19 +13,35 @@
 
 Syntax:
 
-fix ID group-ID wall/lj93 style coord epsilon sigma cutoff 
+fix ID group-ID wall/lj93 style coord epsilon sigma cutoff keyword values ... 
 
-ID, group-ID are documented in fix command
-
wall/lj93 = style name of this fix command
-
style = xlo or xhi or ylo or yhi or zlo or zhi
-
coord = position of wall
-
epsilon = Lennard-Jones epsilon for wall-particle interaction
-
sigma = Lennard-Jones sigma for wall-particle interaction
-
cutoff = distance from wall at which wall-particle interaction is cut off 
+ID, group-ID are documented in fix command 
+
+
wall/lj93 = style name of this fix command 
+
+
style = xlo or xhi or ylo or yhi or zlo or zhi 
+
+
coord = position of wall 
+
+
epsilon = Lennard-Jones epsilon for wall-particle interaction 
+
+
sigma = Lennard-Jones sigma for wall-particle interaction 
+
+
cutoff = distance from wall at which wall-particle interaction is cut off (distance units) 
+
+
one or more keyword/value pairs may be appended 
+
+
keyword = vel 
+
+  vel args = v
+    v = velocity of wall in perpendicular direction (velocity units) 
+
+
 
 Examples:
 
-fix wallhi all wall/lj93 xhi 10.0 1.0 1.0 2.5 
+fix wallhi all wall/lj93 xhi 10.0 1.0 1.0 2.5
+fix leftwall all wall/lj93 zlo 0.0  1.0 1.0 0.858 vel 1.0 
 
 Description:
 
@@ -45,6 +61,14 @@
 The wall potential is shifted so that the energy of a wall-particle
 interaction is 0.0 at the cutoff distance.
 
+If the vel keyword is specified, the position of wall will move
+during the simulation, based on its initial position (coord) and the
+specified velocity (vel).  Xlo or xhi walls move in the x
+direction with whatever sign you give the v argument.  Ditto for y
+and z walls.  Note that if you do multiple runs, the initial
+position of the wall does not change, so it will continue to move at
+the specified velocity.
+
 Restart, fix_modify, output, run start/stop, minimize info:
 
 No information about this fix is written to binary restart
@@ -81,6 +105,8 @@
 
fix wall/reflect, fix
 wall/lj126
 
-Default: none
+
Default:
+
+The option defaults are vel = 0.
 
 
diff -Naur lammps-7Oct08/doc/fix_wall_lj93.txt lammps-8Oct08/doc/fix_wall_lj93.txt
--- lammps-7Oct08/doc/fix_wall_lj93.txt	2008-10-01 10:07:35.000000000 -0600
+++ lammps-8Oct08/doc/fix_wall_lj93.txt	2008-10-06 08:33:34.000000000 -0600
@@ -10,19 +10,25 @@
 
 [Syntax:]
 
-fix ID group-ID wall/lj93 style coord epsilon sigma cutoff :pre
+fix ID group-ID wall/lj93 style coord epsilon sigma cutoff keyword values ... :pre
 
-ID, group-ID are documented in "fix"_fix.html command
-wall/lj93 = style name of this fix command
-style = {xlo} or {xhi} or {ylo} or {yhi} or {zlo} or {zhi}
-coord = position of wall
-epsilon = Lennard-Jones epsilon for wall-particle interaction
-sigma = Lennard-Jones sigma for wall-particle interaction
-cutoff = distance from wall at which wall-particle interaction is cut off :ul
+ID, group-ID are documented in "fix"_fix.html command :ulb,l
+wall/lj93 = style name of this fix command :l
+style = {xlo} or {xhi} or {ylo} or {yhi} or {zlo} or {zhi} :l
+coord = position of wall :l
+epsilon = Lennard-Jones epsilon for wall-particle interaction :l
+sigma = Lennard-Jones sigma for wall-particle interaction :l
+cutoff = distance from wall at which wall-particle interaction is cut off (distance units) :l
+one or more keyword/value pairs may be appended :l
+keyword = {vel} :l
+  {vel} args = v
+    v = velocity of wall in perpendicular direction (velocity units) :pre
+:ule
 
 [Examples:]
 
-fix wallhi all wall/lj93 xhi 10.0 1.0 1.0 2.5 :pre
+fix wallhi all wall/lj93 xhi 10.0 1.0 1.0 2.5
+fix leftwall all wall/lj93 zlo 0.0  1.0 1.0 0.858 vel 1.0 :pre
 
 [Description:]
 
@@ -42,6 +48,14 @@
 The wall potential is shifted so that the energy of a wall-particle
 interaction is 0.0 at the cutoff distance.
 
+If the {vel} keyword is specified, the position of wall will move
+during the simulation, based on its initial position (coord) and the
+specified velocity (vel).  {Xlo} or {xhi} walls move in the x
+direction with whatever sign you give the {v} argument.  Ditto for {y}
+and {z} walls.  Note that if you do multiple runs, the initial
+position of the wall does not change, so it will continue to move at
+the specified velocity.
+
 [Restart, fix_modify, output, run start/stop, minimize info:]
 
 No information about this fix is written to "binary restart
@@ -78,4 +92,6 @@
 "fix wall/reflect"_fix_wall_reflect.html, "fix
 wall/lj126"_fix_wall_lj126.html
 
-[Default:] none
+[Default:]
+
+The option defaults are vel = 0.
diff -Naur lammps-7Oct08/src/fix_wall_lj126.cpp lammps-8Oct08/src/fix_wall_lj126.cpp
--- lammps-7Oct08/src/fix_wall_lj126.cpp	2008-02-19 08:35:29.000000000 -0700
+++ lammps-8Oct08/src/fix_wall_lj126.cpp	2008-10-06 08:22:34.000000000 -0600
@@ -33,7 +33,7 @@
 FixWallLJ126::FixWallLJ126(LAMMPS *lmp, int narg, char **arg) :
   Fix(lmp, narg, arg)
 {
-  if (narg != 8) error->all("Illegal fix wall/lj126 command");
+  if (narg < 8) error->all("Illegal fix wall/lj126 command");
 
   scalar_flag = 1;
   vector_flag = 1;
@@ -42,6 +42,8 @@
   extscalar = 1;
   extvector = 1;
 
+  // set defaults
+
   if (strcmp(arg[3],"xlo") == 0) {
     dim = 0;
     side = -1;
@@ -62,11 +64,24 @@
     side = 1;
   } else error->all("Illegal fix wall/lj126 command");
 
-  coord = atof(arg[4]);
+  coord0 = atof(arg[4]);
   epsilon = atof(arg[5]);
   sigma = atof(arg[6]);
   cutoff = atof(arg[7]);
 
+  // read options
+
+  vel = 0.0;
+
+  int iarg = 8;
+  while (iarg < narg) {
+    if (strcmp(arg[iarg],"vel") == 0) {
+      if (iarg+2 > narg) error->all("Illegal fix wall/lj126 command");
+      vel = atof(arg[iarg+1]);
+      iarg += 2;
+    } else error->all("Illegal fix wall/lj126 command");
+  }
+
   coeff1 = 48.0 * epsilon * pow(sigma,12.0);
   coeff2 = 24.0 * epsilon * pow(sigma,6.0);
   coeff3 = 4.0 * epsilon * pow(sigma,12.0);
@@ -140,6 +155,12 @@
   wall[0] = wall[1] = wall[2] = wall[3] = 0.0;
   wall_flag = 0;
 
+  // coord = current position of wall
+  // coord0 = initial position of wall
+  
+  double delt = (update->ntimestep - update->beginstep) * update->dt;
+  double coord = coord0 + delt*vel;
+
   for (int i = 0; i < nlocal; i++)
     if (mask[i] & groupbit) {
       if (side == -1) delta = x[i][dim] - coord;
diff -Naur lammps-7Oct08/src/fix_wall_lj126.h lammps-8Oct08/src/fix_wall_lj126.h
--- lammps-7Oct08/src/fix_wall_lj126.h	2008-01-09 14:56:57.000000000 -0700
+++ lammps-8Oct08/src/fix_wall_lj126.h	2008-10-03 20:38:52.000000000 -0600
@@ -36,6 +36,7 @@
   double coord,epsilon,sigma,cutoff;
   double coeff1,coeff2,coeff3,coeff4,offset;
   double wall[4],wall_all[4];
+  double vel,coord0;
   int wall_flag;
   int nlevels_respa;
 };
diff -Naur lammps-7Oct08/src/fix_wall_lj93.cpp lammps-8Oct08/src/fix_wall_lj93.cpp
--- lammps-7Oct08/src/fix_wall_lj93.cpp	2008-01-09 14:56:57.000000000 -0700
+++ lammps-8Oct08/src/fix_wall_lj93.cpp	2008-10-06 08:22:34.000000000 -0600
@@ -29,7 +29,7 @@
 FixWallLJ93::FixWallLJ93(LAMMPS *lmp, int narg, char **arg) :
   Fix(lmp, narg, arg)
 {
-  if (narg != 8) error->all("Illegal fix wall/lj93 command");
+  if (narg < 8) error->all("Illegal fix wall/lj93 command");
 
   scalar_flag = 1;
   vector_flag = 1;
@@ -38,6 +38,8 @@
   extscalar = 1;
   extvector = 1;
 
+  // set defaults
+
   if (strcmp(arg[3],"xlo") == 0) {
     dim = 0;
     side = -1;
@@ -58,11 +60,24 @@
     side = 1;
   } else error->all("Illegal fix wall/lj93 command");
 
-  coord = atof(arg[4]);
+  coord0 = atof(arg[4]);
   epsilon = atof(arg[5]);
   sigma = atof(arg[6]);
   cutoff = atof(arg[7]);
 
+  // read options 
+
+  vel = 0.0;
+
+  int iarg = 8;
+  while (iarg < narg) {
+    if (strcmp(arg[iarg],"vel") == 0) {
+      if (iarg+2 > narg) error->all("Illegal fix wall/lj93 command");
+      vel = atof(arg[iarg+1]);
+      iarg += 2;
+    } else error->all("Illegal fix wall/lj93 command");
+  }
+
   coeff1 = 6.0/5.0 * epsilon * pow(sigma,9.0);
   coeff2 = 3.0 * epsilon * pow(sigma,3.0);
   coeff3 = 2.0/15.0 * epsilon * pow(sigma,9.0);
@@ -137,6 +152,12 @@
   wall[0] = wall[1] = wall[2] = wall[3] = 0.0;
   wall_flag = 0;
 
+  // coord = current position of wall
+  // coord0 = initial position of wall
+
+  double delt = (update->ntimestep - update->beginstep) * update->dt;
+  double coord = coord0 + delt*vel;
+
   for (int i = 0; i < nlocal; i++)
     if (mask[i] & groupbit) {
       if (side == -1) delta = x[i][dim] - coord;
diff -Naur lammps-7Oct08/src/fix_wall_lj93.h lammps-8Oct08/src/fix_wall_lj93.h
--- lammps-7Oct08/src/fix_wall_lj93.h	2008-01-09 14:56:57.000000000 -0700
+++ lammps-8Oct08/src/fix_wall_lj93.h	2008-10-03 20:38:52.000000000 -0600
@@ -37,6 +37,7 @@
   double coord,epsilon,sigma,cutoff;
   double coeff1,coeff2,coeff3,coeff4,offset;
   double wall[4],wall_all[4];
+  double vel,coord0;
   int wall_flag;
   int nlevels_respa;
 };