From e85b65f387ebfe19c919b885b5da0359b893ce6f Mon Sep 17 00:00:00 2001
From: sjplimp <sjplimp@f3b2605a-c512-4ea7-a41b-209d697bcdaa>
Date: Wed, 1 Dec 2010 16:59:10 +0000
Subject: [PATCH] git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@5349
 f3b2605a-c512-4ea7-a41b-209d697bcdaa

---
 src/KSPACE/pair_buck_coul_long.cpp | 30 ++++++++++++++++++++++++++++++
 src/fix_wall_reflect.cpp           |  2 +-
 src/pair_buck.cpp                  | 30 ++++++++++++++++++++++++++++++
 src/pair_buck_coul_cut.cpp         | 30 ++++++++++++++++++++++++++++++
 4 files changed, 91 insertions(+), 1 deletion(-)

diff --git a/src/KSPACE/pair_buck_coul_long.cpp b/src/KSPACE/pair_buck_coul_long.cpp
index a865a583b8..800900cdc2 100644
--- a/src/KSPACE/pair_buck_coul_long.cpp
+++ b/src/KSPACE/pair_buck_coul_long.cpp
@@ -287,6 +287,36 @@ double PairBuckCoulLong::init_one(int i, int j)
   buck2[j][i] = buck2[i][j];
   offset[j][i] = offset[i][j];
 
+  // compute I,J contribution to long-range tail correction 
+  // count total # of atoms of type I and J via Allreduce 
+
+  if (tail_flag) {
+    int *type = atom->type;
+    int nlocal = atom->nlocal;
+
+    double count[2],all[2];
+    count[0] = count[1] = 0.0;
+    for (int k = 0; k < nlocal; k++) {
+      if (type[k] == i) count[0] += 1.0;
+      if (type[k] == j) count[1] += 1.0;
+    }
+    MPI_Allreduce(count,all,2,MPI_DOUBLE,MPI_SUM,world);
+
+    double PI = 4.0*atan(1.0);
+    double rho1 = rho[i][j];
+    double rho2 = rho1*rho1;
+    double rho3 = rho2*rho1;
+    double rc = cut_lj[i][j];
+    double rc2 = rc*rc;
+    double rc3 = rc2*rc;
+    etail_ij = 2.0*PI*all[0]*all[1]*
+      (a[i][j]*exp(-rc/rho1)*rho1*(rc2 + 2.0*rho1*rc + 2.0*rho2) - 
+       c[i][j]/(3.0*rc3));
+    ptail_ij = (-1/3.0)*2.0*PI*all[0]*all[1]*
+      (-a[i][j]*exp(-rc/rho1)*
+       (rc3 + 3.0*rho1*rc2 + 6.0*rho2*rc + 6.0*rho3) + 2.0*c[i][j]/rc3);
+  }
+  
   return cut;
 }
 
diff --git a/src/fix_wall_reflect.cpp b/src/fix_wall_reflect.cpp
index 95407231b0..fa74faf48a 100644
--- a/src/fix_wall_reflect.cpp
+++ b/src/fix_wall_reflect.cpp
@@ -213,7 +213,7 @@ void FixWallReflect::post_integrate()
 	    v[i][dim] = -v[i][dim];
 	  }
 	} else {
-	  if (x[i][0] > coord) {
+	  if (x[i][dim] > coord) {
 	    x[i][dim] = coord - (x[i][dim] - coord);
 	    v[i][dim] = -v[i][dim];
 	  }
diff --git a/src/pair_buck.cpp b/src/pair_buck.cpp
index f8c48ca1c5..8d02aa2b84 100644
--- a/src/pair_buck.cpp
+++ b/src/pair_buck.cpp
@@ -242,6 +242,36 @@ double PairBuck::init_one(int i, int j)
   buck2[j][i] = buck2[i][j];
   offset[j][i] = offset[i][j];
 
+  // compute I,J contribution to long-range tail correction 
+  // count total # of atoms of type I and J via Allreduce 
+
+  if (tail_flag) {
+    int *type = atom->type;
+    int nlocal = atom->nlocal;
+
+    double count[2],all[2];
+    count[0] = count[1] = 0.0;
+    for (int k = 0; k < nlocal; k++) {
+      if (type[k] == i) count[0] += 1.0;
+      if (type[k] == j) count[1] += 1.0;
+    }
+    MPI_Allreduce(count,all,2,MPI_DOUBLE,MPI_SUM,world);
+
+    double PI = 4.0*atan(1.0);
+    double rho1 = rho[i][j];
+    double rho2 = rho1*rho1;
+    double rho3 = rho2*rho1;
+    double rc = cut[i][j];
+    double rc2 = rc*rc;
+    double rc3 = rc2*rc;
+    etail_ij = 2.0*PI*all[0]*all[1]*
+      (a[i][j]*exp(-rc/rho1)*rho1*(rc2 + 2.0*rho1*rc + 2.0*rho2) - 
+       c[i][j]/(3.0*rc3));
+    ptail_ij = (-1/3.0)*2.0*PI*all[0]*all[1]*
+      (-a[i][j]*exp(-rc/rho1)*
+       (rc3 + 3.0*rho1*rc2 + 6.0*rho2*rc + 6.0*rho3) + 2.0*c[i][j]/rc3);
+  }
+  
   return cut[i][j];
 }
 
diff --git a/src/pair_buck_coul_cut.cpp b/src/pair_buck_coul_cut.cpp
index 9bcec376ea..4d57d22186 100644
--- a/src/pair_buck_coul_cut.cpp
+++ b/src/pair_buck_coul_cut.cpp
@@ -296,6 +296,36 @@ double PairBuckCoulCut::init_one(int i, int j)
   buck2[j][i] = buck2[i][j];
   offset[j][i] = offset[i][j];
 
+  // compute I,J contribution to long-range tail correction 
+  // count total # of atoms of type I and J via Allreduce 
+
+  if (tail_flag) {
+    int *type = atom->type;
+    int nlocal = atom->nlocal;
+
+    double count[2],all[2];
+    count[0] = count[1] = 0.0;
+    for (int k = 0; k < nlocal; k++) {
+      if (type[k] == i) count[0] += 1.0;
+      if (type[k] == j) count[1] += 1.0;
+    }
+    MPI_Allreduce(count,all,2,MPI_DOUBLE,MPI_SUM,world);
+
+    double PI = 4.0*atan(1.0);
+    double rho1 = rho[i][j];
+    double rho2 = rho1*rho1;
+    double rho3 = rho2*rho1;
+    double rc = cut_lj[i][j];
+    double rc2 = rc*rc;
+    double rc3 = rc2*rc;
+    etail_ij = 2.0*PI*all[0]*all[1]*
+      (a[i][j]*exp(-rc/rho1)*rho1*(rc2 + 2.0*rho1*rc + 2.0*rho2) - 
+       c[i][j]/(3.0*rc3));
+    ptail_ij = (-1/3.0)*2.0*PI*all[0]*all[1]*
+      (-a[i][j]*exp(-rc/rho1)*
+       (rc3 + 3.0*rho1*rc2 + 6.0*rho2*rc + 6.0*rho3) + 2.0*c[i][j]/rc3);
+  }
+  
   return cut;
 }