git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@4549 f3b2605a-c512-4ea7-a41b-209d697bcdaa

tools/eff/structure_generators/h2.pl

@@ -0,0 +1,67 @@
+#!/usr/bin/perl
+
+# Usage: h2.pl <nx> <ny> <nz> <rs> > data.h2
+#
+# Generates rectangular lattice of hydrogen atoms, # in each direction = nx,
+# with Wigner radius rs.
+#    ...
+# Shifts H atoms in alternating directions so they form H2 molecule
+# starting structures.
+
+$nx = shift(@ARGV);
+$ny = shift(@ARGV);
+$nz = shift(@ARGV);
+$rs = shift(@ARGV);
+
+$L  = 1.6119919540164693 * $rs;  # length of unit cell ((4/3 pi)^(1/3)
+$re = 1.823572;                  # electron radius
+
+$dshift = 0.5;
+
+$idx = 0;
+for ($x = 0; $x < $nx; $x++)
+{
+  for ($y = 0; $y < $ny; $y++)
+  {
+    $dsign = 1; 
+    for ($z = 0; $z < $nz; $z++)
+    {
+      $xnuc[$idx] = $x * $L + 0.5 * $L; 
+      $ynuc[$idx] = $y * $L + 0.5 * $L;
+      $znuc[$idx] = $z * $L + 0.5 * $L + $dshift * $dsign;
+      $dsign = -$dsign;
+      $idx++;
+    }
+  }
+} 
+
+$numnuc = $idx;
+
+# Print length of supercell
+
+printf("Created with h2.pl\n\n");
+printf("%d atoms\n",$numnuc*2);
+printf("2 atom types\n\n");
+printf("%f %f xlo xhi\n", 0, $L * $nx);
+printf("%f %f ylo yhi\n", 0, $L * $ny);
+printf("%f %f zlo zhi\n\n", 0, $L * $nz);
+printf("Masses\n\n");
+printf("1 1.007940\n");
+printf("2 1.000000\n\n");
+printf("Atoms\n\n");
+
+$j=0;
+
+# Print out the nuclei and the core electrons
+for ($i = 0; $i < $numnuc; $i++)
+{
+  printf("%i %i %f %f %f %f %i %f\n", $j+=1, 1, $xnuc[$i], $ynuc[$i], $znuc[$i], 1.0, 0, 0.0);
+}
+
+$spin = 1;
+for ($i = 0; $i < $numnuc; $i++)
+{
+  if ($spin == 1) {$spin = -1;} else {$spin = 1;}
+  printf("%i %i %f %f %f %f %i %f\n", $j+=1, 2, $xnuc[$i], $ynuc[$i], $znuc[$i], 0.0, $spin, $re);
+}
+