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#                                                                     #
#  Example:  Constructing an HCP lattice                              #
#                                                                     #
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#                                                                     #
#    This file gives an example of how to create an HCP lattice.      #
#  It then uses the supplied RuAl potential to calculate the          #
#  lattice energy of HCP Ru.                                          #
#                                                                     #
#    This example generates an HCP lattice that has the Y axis        #
#  along a nearest neighbor direction, and the Z axis normal to       #
#  the close packed planes.                                           #
#                                                                     #
#######################################################################

#  Set up some useful constants for this potential
calc  Ru=1
calc  A=2.71
calc  C=4.29

#  Form hcp unit cell
box 4 6 4
fill particle 4
Ru   1/12   1/4   1/4
Ru   7/12   3/4   1/4
Ru   5/12   1/4   3/4
Ru  11/12   3/4   3/4
fill go
scale A*sqrt(3) A C

#  Write system energy 
read ../rual.txt
write energy