Name change, add example

examples/LEPTON/in.efield-lepton

@@ -0,0 +1,49 @@
+# Point dipoles in a 3d box with an external potential (ignoring dipolar interactions)
+
+units		lj
+atom_style	hybrid sphere dipole
+dimension	3
+boundary	s s s
+region		box block -2 2 -2 2 -2 2
+
+create_box	1 box
+create_atoms 	1 random 100 12345 NULL
+
+# need both mass settings due to hybrid atom style
+mass		1 1.0
+set		group all mass 1.0
+set		group all diameter 0.1
+
+set		group all dipole/random 98934 0.01
+pair_style	none
+
+velocity	all create 0.0 87287 mom yes rot yes
+
+fix		1 all nve/sphere update dipole
+
+###############################################################################################################
+## Yukawa potential
+#fix		2 all efield/lepton "A*exp(-B*r)/r; r=abs(sqrt(x^2+y^2+z^2)); A = 0.1; B = 5" step 1e-8
+
+## Gradually increasing uniform field 
+#variable	E equal ramp(0,1)
+#fix 		2 all efield/lepton "-v_E*(x+y+z)"
+
+## Linear gradient field
+fix 		2 all efield/lepton "-1/6*x^3" step 1e-6
+
+fix_modify 	2 energy yes
+
+###############################################################################################################
+
+timestep	1e-3
+
+compute		erot all erotate/sphere
+variable	etotal equal "ke + c_erot + pe" # thermo etotal doesn't include erot
+thermo_style 	custom step temp ke c_erot pe v_etotal
+thermo		500
+thermo_modify 	norm no
+
+#dump        	1 all custom 500 dump.dipole id x y z diameter mux muy muz fx fy fz tqx tqy tqz
+
+run		10000