first few pieces of pair style python

examples/python/lj-melt-potential.py

@@ -0,0 +1,28 @@
+from __future__ import print_function
+
+class LAMMPSLJCutPotential(object):
+
+    def __init__(self):
+        self.pmap=dict()
+        # coefficients: epsilon, sigma
+        self.coeff = {'lj'  : {'lj'  : (1.0,1.0),
+                               'NULL': (0.0,1.0)},
+                      'NULL': {'lj'  : (0.0,1.0),
+                               'NULL': (0.0,1.0)}}
+
+    def map_coeff(self,type,name):
+        if self.coeff.has_key(name):
+           print("map type %d to name %s" % (type,name))
+           self.pmap[type] = name
+        else:
+           print("cannot match atom type",name)
+
+    def compute_force(self,r,itype,jtype,factor_lj):
+        return 0.0
+
+    def compute_energy(self,r,itype,jtype,factor_lj):
+        return 0.0
+
+lammps_pair_style = LAMMPSLJCutPotential()
+print ("lj-melt potential file loaded")
+