diff --git a/src/main/qb.cc b/src/main/qb.cc
index ad4aa886..60987ca6 100644
--- a/src/main/qb.cc
+++ b/src/main/qb.cc
@@ -84,6 +84,7 @@ using namespace std;
 #include <ui/LockCmd.h>
 #include <ui/UnlockCmd.h>
 #include <ui/SetVelCmd.h>
+#include <ui/SetPosCmd.h>
 #include <ui/ComputeMLWFCmd.h>
 #include <ui/AngleCmd.h>
 #include <ui/ConstraintCmd.h>
@@ -347,6 +348,7 @@ int main(int argc, char **argv, char **envp)
   ui->addCmd(new LockCmd(s));
   ui->addCmd(new UnlockCmd(s));
   ui->addCmd(new SetVelCmd(s));
+  ui->addCmd(new SetPosCmd(s));
   ui->addCmd(new ComputeMLWFCmd(s));
   ui->addCmd(new ConstraintCmd(s));
   ui->addCmd(new ShiftWFCmd(s));
diff --git a/src/qball/qbLink.cc b/src/qball/qbLink.cc
index 1ed67273..d17ed2da 100644
--- a/src/qball/qbLink.cc
+++ b/src/qball/qbLink.cc
@@ -87,6 +87,7 @@ using namespace std;
 #include <ui/LockCmd.h>
 #include <ui/UnlockCmd.h>
 #include <ui/SetVelCmd.h>
+#include <ui/SetPosCmd.h>
 #include <ui/ComputeMLWFCmd.h>
 #include <ui/AngleCmd.h>
 #include <ui/ConstraintCmd.h>
diff --git a/src/ui/Makefile.am b/src/ui/Makefile.am
index 506ec139..b7cc9c42 100644
--- a/src/ui/Makefile.am
+++ b/src/ui/Makefile.am
@@ -39,6 +39,7 @@ noinst_HEADERS =                            \
 	SavesysCmd.h \
 	SetCmd.h \
 	SetVelCmd.h \
+	SetPosCmd.h \
 	ShiftWFCmd.h \
 	SpeciesCmd.h \
 	StatusCmd.h \
diff --git a/src/ui/SetPosCmd.h b/src/ui/SetPosCmd.h
new file mode 100644
index 00000000..83544c0a
--- /dev/null
+++ b/src/ui/SetPosCmd.h
@@ -0,0 +1,122 @@
+////////////////////////////////////////////////////////////////////////////////  
+// Copyright (c) 2013, Lawrence Livermore National Security, LLC. 
+// qb@ll:  Qbox at Lawrence Livermore
+//
+// This file is part of qb@ll.
+//
+// Produced at the Lawrence Livermore National Laboratory. 
+// Written by Erik Draeger (draeger1@llnl.gov) and Francois Gygi (fgygi@ucdavis.edu).
+// Based on the Qbox code by Francois Gygi Copyright (c) 2008 
+// LLNL-CODE-635376. All rights reserved. 
+//
+// qb@ll is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details, in the file COPYING in the
+// root directory of this distribution or <http://www.gnu.org/licenses/>.
+//
+////////////////////////////////////////////////////////////////////////////////
+//
+// SetVelCmd.h:
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <config.h>
+
+#ifndef SETPOSCMD_H
+#define SETPOSCMD_H
+
+#include <iostream>
+#include <cstdlib>
+#include <string>
+using namespace std;
+
+#include <ui/UserInterface.h>
+#include <qball/Sample.h>
+#include <qball/Species.h>
+#include <qball/MMSpecies.h>
+#include <qball/Atom.h>
+
+class SetPosCmd : public Cmd {
+  public:
+
+  Sample *s;
+
+  SetPosCmd(Sample *sample) : s(sample) { };
+
+  char const*name(void) const { return "set_position"; }
+
+  char const*help_msg(void) const {
+    return 
+    "\n lock\n\n"
+    " syntax: set_position [atom name] [x] [y] [z]\n\n"
+    "   The set_position command sets the velocity for a given atom.\n\n";
+  }
+
+
+  int action(int argc, char **argv) {
+    string name;
+
+    string pos_unit_name = "bohr";
+//    string vel_unit_name = "atomicvelocity";
+ 
+    if ( argc != 5 && argc != 6) {
+      ui->error("<!-- use: set_position [atom name] [x] [y] [z] [units] -->");
+      return 1;
+    }
+
+    if (argc == 5) {
+      ui->warning("Units missing for the set_velocity command, assuming 'atomicvelocity'.");
+    } else {
+      pos_unit_name = string(argv[5]);
+    }
+    
+    Unit pos_unit(Dimensions::length, pos_unit_name);
+//    Unit vel_unit(Dimensions::velocity, vel_unit_name);
+    
+    if(!pos_unit.exists()) {
+      ui->error("Unknown position unit '" + pos_unit_name + "'.");
+      return 1;
+    }
+    
+    name = argv[1];
+    double x = atof(argv[2]);
+    double y = atof(argv[3]);
+    double z = atof(argv[4]);
+    D3vector newpos(x,y,z);
+
+    newpos = pos_unit.to_atomic(newpos);
+    
+    if (s->atoms.findAtom(name) ) {
+      Atom *a = s->atoms.findAtom(name);
+
+      a->set_position(newpos);
+      if ( ui->oncoutpe() )
+        cout << "<!-- Atom " << a->name() << " position set to " << newpos << " -->" << endl;
+    }
+    else if (s->atoms.findMMAtom(name) ) {
+      Atom *a = s->atoms.findMMAtom(name);
+
+      a->set_position(newpos);
+      if ( ui->oncoutpe() )
+        cout << "<!-- Atom " << a->name() << " position set to " << newpos << " -->" << endl;
+    }
+    else {
+      if ( ui->oncoutpe() )
+        cout << "<ERROR>SetPosCmd:  " << name << " not found!</ERROR>" << endl;
+      return 1;
+    }
+    return 0;
+  }
+
+};
+#endif
+
+// Local Variables:
+// mode: c++
+// End:
diff --git a/src/ui/SetVelCmd.h b/src/ui/SetVelCmd.h
index 8bf57d73..e4f6734b 100644
--- a/src/ui/SetVelCmd.h
+++ b/src/ui/SetVelCmd.h
@@ -78,7 +78,7 @@ class SetVelCmd : public Cmd {
     Unit vel_unit(Dimensions::velocity, vel_unit_name);
     
     if(!vel_unit.exists()) {
-      ui->error("Unknown energy unit '" + vel_unit_name + "'.");
+      ui->error("Unknown velocity unit '" + vel_unit_name + "'.");
       return 1;
     }