############################# INITIALIZATION ###############################

     units         metal
     dimension     3
     boundary      p p p
     atom_style     atomic
     atom_modify     map array sort 0 0.0
     neighbor       0.3 bin
     neigh_modify   every 1 delay 0 check yes

#================================================================
#----------------Potential & Structure---------------------------
#================================================================
lattice         fcc 3.604 origin 0.25 0.25 0.25
#region          box block 0 80 0 40 0 40     #bigger block contains Ni
#region          Inconel block 0 40 0 40 0 40   #block of inconel half along X, OTHERS SAME 
region          box block 0 20 0 10 0 10     #bigger block contain Ni
region          Inconel block 0 10 0 10 0 10   #block of inconel half along X, OTHERS SAME
create_box      3 box
create_atoms    1 box

#region  pore sphere 40 20 20 5.5 side in
#delete_atoms region pore

group inconel region Inconel

set   group inconel type/fraction 3 0.47 1234         #Fe
set   group inconel type/fraction 2  0.21 12345       #Cr

mass 1 58.6934 # Ni
mass 2 51.9961 # Cr
mass 3 55.8450 # Fe

pair_style       hybrid/overlay eam/alloy zbl  0.90 1.250
pair_coeff * *   eam/alloy FeNiCr.eam.alloy Ni Cr Fe
pair_coeff 1 1   zbl 28.0 28.0
pair_coeff 2 2   zbl 24.0 24.0
pair_coeff 3 3   zbl 26.0 26.0
pair_coeff 1 2   zbl 28.0 24.0
pair_coeff 1 3   zbl 28.0 26.0
pair_coeff 2 3   zbl 24.0 26.0

variable natoms equal "count(all)"					# Total number of atoms 
print "Number of atoms = ${natoms}"
variable T equal ${natoms}
variable t equal 1

variable randnum equal random(0,1,${seed1})				# Choosing a random number
variable rand equal ${randnum}

variable denom equal $t/$T
print "Denominator = ${denom}"
variable calc equal ${rand}/${denom}
print "Calc = ${calc}"	
variable i equal ${calc}+1						# Choosing the random atom based on the random number

# ---------------------------------------------
# ASSIGNING THE ID, TYPE AND X,Y,Z COORDINATES OF THE CHOSEN ATOM TO VARIABLES
# ---------------------------------------------
    	variable xi equal x[v_i]						# Extracting the x-coordinate of the atom
    	variable yi equal y[v_i]						# Extracting the y-coordinate of the atom
   	variable zi equal z[v_i]						# Extracting the z-coordinate of the atom
    	variable idi equal id[v_i]						# Extracting the ID of the atom
    	variable typei equal type[v_i]						# Extracting the type of the atom

    	variable atom1 equal ${typei}						# Assigning the atom type to the variable 'atom1'
    	variable ID1 equal ${idi}						# Assigning the atom ID to the variable 'ID_1'
    	variable x0 equal ${xi}							# Assigning the x-coordinate of the atom  to the variable 'x0'
    	variable y0 equal ${yi}							# Assigning the y-coordinate of the atom  to the variable 'y0'	
   	variable z0 equal ${zi}   						# Assigning the z-coordinate of the atom  to the variable 'z0'

	region 1 sphere  ${x0} ${y0} ${z0} $l side in
    	group nnatoms region 1 							# Grouping the nearest-neighbour atoms of the randomly-chosen first atom

# ---------------------------------------------------------------------	
# COUNTING THE NUMBER OF ATOMS WITHIN THE NEAREST-NEIGHBOUR RADIUS
# ---------------------------------------------------------------------	
      	variable num_nnatoms equal "count(nnatoms)"
    	variable nn equal ${num_nnatoms}