HEA Calculation.lmp

# Site-by-site substitution scan in a multicomponent HEA
# The original atom types are stored once, each site is temporarily converted
# to the target type, the total energy is evaluated, and the original type is
# restored before moving to the next site.

units           metal
atom_style      atomic
boundary        p p p
read_data       HEA.lmp

# Interatomic potential
pair_style      meam
pair_coeff      * * library.meam Co Ni Cr Fe Mn CoNiCrFeMn.meam Co Ni Cr Fe Mn

# Store the original atom types once for later restoration
fix             backup_types all store/state 0 type
variable        original_type atom f_backup_types

# Loop control
variable        total_atoms equal count(all)
variable        atom_id loop ${total_atoms}
variable        totalenergy equal pe

# Here the test substitution species is type 1
print           "# Atom_ID Potential_Energy" file hea_site_substitution_energies.txt
thermo          1000
thermo_style    custom step pe

label           loop_start

# Temporarily assign the current atom to the test species
set             atom ${atom_id} type 1
minimize        0 1.0e-12 1000 1000
# Recompute the energy without advancing the trajectory
run             0
print           "${atom_id} ${totalenergy}" append hea_site_substitution_energies.txt

# Restore the original atom type
set             atom ${atom_id} type v_original_type

next            atom_id
jump            SELF loop_start

print           "Done."

# Example run command:
# mpiexec -np 4 lmp -in in.lmp -pk omp 4 -sf omp