#######################################################################
#                                                                     #
#  Example:    Using Stillinger-Weber's Si Potential                  #
#                                                                     #
#  Reference:  Computer simulation of local order in condensed        #
#              phases of silicon, F. H. Stillinger, T. A. Weber,      #
#              Phys. Rev. B 31 (8) 5262 (1985)                        #
#                                                                     #
#######################################################################
#                                                                     #
#    This file gives an example of how to create a Si diamond         #
#  structure and how to load the Stillinger Weber Si potential.       #
#                                                                     #
#######################################################################
#
#  Set constants for Stillinger-Weber Si potential
#
potential set still

#  Use old neighbor search algorithm to accomodate small atomic array
nsearch sort

calc  DTIME=0.5e-15
calc  Si=1
calc  MassSi=28.086
calc  A0=5.428
eunit erg


#  Form diamond unit cell
box 2 2 2
particle  8
 Si  0.125 0.125 0.125
 Si  0.125 0.625 0.625
 Si  0.625 0.125 0.625
 Si  0.625 0.625 0.125
 Si  0.375 0.375 0.375
 Si  0.375 0.875 0.875
 Si  0.875 0.375 0.875
 Si  0.875 0.875 0.375
dup  1  1 0 0
dup  1  0 1 0
dup  1  0 0 1

#  Scale to the unit cell length of diamond CSi
scale A0

#  Set particle masses
select type Si
mass MassSi

#  Set simulation step size
dtime DTIME

#  Instruct XMD to save energy every CMD step in file still.e
esave 1 still.e

#  Initialize velocities to 1000K
itemp 1000

#  Set clamp off (adiabatic simulation)
clamp off

# Equilibrate particles for 500 step
cmd 500