From c200e187b53b9729081797cc97c91c923d745651 Mon Sep 17 00:00:00 2001
From: sjplimp <sjplimp@f3b2605a-c512-4ea7-a41b-209d697bcdaa>
Date: Mon, 22 Feb 2016 23:18:57 +0000
Subject: [PATCH] git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@14665
 f3b2605a-c512-4ea7-a41b-209d697bcdaa

---
 src/improper_zero.cpp | 92 +++++++++++++++++++++++++++++++++++++++++++
 src/improper_zero.h   | 57 +++++++++++++++++++++++++++
 2 files changed, 149 insertions(+)
 create mode 100644 src/improper_zero.cpp
 create mode 100644 src/improper_zero.h

diff --git a/src/improper_zero.cpp b/src/improper_zero.cpp
new file mode 100644
index 0000000000..3931bf20a1
--- /dev/null
+++ b/src/improper_zero.cpp
@@ -0,0 +1,92 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#include <mpi.h>
+#include <math.h>
+#include <stdlib.h>
+#include "improper_zero.h"
+#include "atom.h"
+#include "force.h"
+#include "memory.h"
+#include "error.h"
+
+using namespace LAMMPS_NS;
+
+/* ---------------------------------------------------------------------- */
+
+ImproperZero::ImproperZero(LAMMPS *lmp) : Improper(lmp) {}
+
+/* ---------------------------------------------------------------------- */
+
+ImproperZero::~ImproperZero()
+{
+  if (allocated && !copymode) {
+    memory->destroy(setflag);
+  }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void ImproperZero::compute(int eflag, int vflag)
+{
+  if (eflag || vflag) ev_setup(eflag,vflag);
+  else evflag = 0;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void ImproperZero::allocate()
+{
+  allocated = 1;
+  int n = atom->nimpropertypes;
+
+  memory->create(setflag,n+1,"improper:setflag");
+  for (int i = 1; i <= n; i++) setflag[i] = 0;
+}
+
+/* ----------------------------------------------------------------------
+   set coeffs for one type
+------------------------------------------------------------------------- */
+
+void ImproperZero::coeff(int narg, char **arg)
+{
+  if (narg != 1) error->all(FLERR,"Incorrect args for improper coefficients");
+  if (!allocated) allocate();
+
+  int ilo,ihi;
+  force->bounds(arg[0],atom->nimpropertypes,ilo,ihi);
+
+  int count = 0;
+  for (int i = ilo; i <= ihi; i++) {
+    setflag[i] = 1;
+    count++;
+  }
+
+  if (count == 0) error->all(FLERR,"Incorrect args for improper coefficients");
+}
+
+/* ----------------------------------------------------------------------
+   proc 0 writes out coeffs to restart file
+------------------------------------------------------------------------- */
+
+void ImproperZero::write_restart(FILE *fp) {}
+
+/* ----------------------------------------------------------------------
+   proc 0 reads coeffs from restart file, bcasts them
+------------------------------------------------------------------------- */
+
+void ImproperZero::read_restart(FILE *fp)
+{
+  allocate();
+  for (int i = 1; i <= atom->nimpropertypes; i++) setflag[i] = 1;
+}
diff --git a/src/improper_zero.h b/src/improper_zero.h
new file mode 100644
index 0000000000..7283e858fb
--- /dev/null
+++ b/src/improper_zero.h
@@ -0,0 +1,57 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifdef IMPROPER_CLASS
+
+ImproperStyle(zero,ImproperZero)
+
+#else
+
+#ifndef LMP_IMPROPER_ZERO_H
+#define LMP_IMPROPER_ZERO_H
+
+#include <stdio.h>
+#include "improper.h"
+
+namespace LAMMPS_NS {
+
+class ImproperZero : public Improper {
+ public:
+  ImproperZero(class LAMMPS *);
+  virtual ~ImproperZero();
+  virtual void compute(int, int);
+  virtual void coeff(int, char **);
+  void write_restart(FILE *);
+  void read_restart(FILE *);
+
+ protected:
+  virtual void allocate();
+};
+
+}
+
+#endif
+#endif
+
+/* ERROR/WARNING messages:
+
+W: Improper problem: %d %ld %d %d %d %d
+
+Conformation of the 4 listed improper atoms is extreme; you may want
+to check your simulation geometry.
+
+E: Incorrect args for improper coefficients
+
+Self-explanatory.  Check the input script or data file.
+
+*/