Hi! I’m trying to simulate melting through the interface method, where half of my simulation is liquid and the other half is solid, them being put next to one another should spread the liquid state through the solid half. However I’m unsure how to understand LAMMPS’s output or what to expect from it, and was hoping you could be of assistance!

Below is my LAMMPS input script, my logic was to create a huge box and split it in two, I’d bring both to 1400K using NPT temperature ramps, going 50K to 1400K for the solid box and 4200K to 1400K for the liquid box, then keeping them at 1400K.

My fix 5 has the purpose of printing the thermodynamic results found in the log file, however it seems to only be printing the thermodynamic results of the “solid” box, as it only contains temperatures between 50K and 1400K, how can I track both boxes in a similar manner?

Thank you very much!

# Antoine Rincent, 2019

suffix omp

package omp 1

variable lattconst equal 5.08

variable repetition equal 20

variable temperature1 equal 50

variable temperature2 equal 4200

variable temperature3 equal 1400

variable pression equal 1.0

variable testnum equal 2

variable foldernum equal 9

log EffetNb_{foldernum}_{testnum}.log

# ---------- Initialize Simulation ---------------------

clear

units metal

dimension 3

boundary p p p

atom_style atomic

atom_modify map array

# ---------- Create Atoms ---------------------

lattice fcc ${lattconst}

variable demirepetition equal “v_repetition/2”

region whole block 0 {repetition} 0 {repetition} -{repetition} {repetition} units lattice

create_box 1 whole

region box1_1 block 0 {repetition} 0 {repetition} {demirepetition} {repetition} units lattice

region box1_2 block 0 {repetition} 0 {repetition} -{repetition} -{demirepetition} units lattice

region box2 block 0 {repetition} 0 {repetition} -{demirepetition} {demirepetition} units lattice

lattice fcc ${lattconst} orient x 1 0 0 orient y 0 1 0 orient z 0 0 1

create_atoms 1 region box1_1

create_atoms 1 region box1_2

create_atoms 1 region box2

group liquid region box1_1

group liquid region box1_2

group solid region box2

# ---------- Define Interatomic Potential ---------------------

pair_style eam/alloy

pair_coeff * * Au_GLJ10_3.eam.alloy Au

neighbor 2.0 bin

neigh_modify delay 0 every 1 check yes

delete_atoms overlap 0.35 all all

velocity all create ${temperature1} 420

# ---------- Run Minimization ---------------------

variable iterations equal 1000000

variable thermooutput equal “v_iterations/5000”

variable resultsoutput equal “v_iterations/10000”

variable rdfoutput equal “v_iterations/100”

variable dumpoutput equal 400

timestep 0.001

thermo ${thermooutput}

thermo_style custom step temp enthalpy etotal pe ke press vol cella cellb cellc

thermo_modify norm no

min_style cg

minimize 1e-25 1e-25 5000 10000

compute LIQUIDE_liquid liquid rdf 50 * *

compute LIQUIDE_solid solid rdf 50 * *

fix 1 all ave/time {rdfoutput} 1 {rdfoutput} c_LIQUIDE_liquid[*] file FixAveTime_liquid_{foldernum}_{testnum}.rdf mode vector
fix 2 all ave/time {rdfoutput} 1 {rdfoutput} c_LIQUIDE_solid[*] file FixAveTime_solid_{foldernum}_{testnum}.rdf mode vector

fix 3 liquid npt temp {temperature2} {temperature3} (100*dt) iso {pression} {pression} (1000*dt)
fix 4 solid npt temp {temperature1} {temperature3} (100*dt) iso {pression} {pression} (1000*dt)

dump mydump all xyz {dumpoutput} EffetNb_{foldernum}_${testnum}.xyz

variable iteration equal “step”

variable tempe equal “temp”

variable enth equal “enthalpy”

variable etot equal “etotal”

variable potential equal “pe”

variable kinetic equal “ke”

variable pressure equal “press”

variable volume equal “vol”

variable cellulea equal “cella”

variable celluleb equal “cellb”

variable cellulec equal “cellc”

fix 5 all print {resultsoutput} "{iteration} {tempe} {enth} {etot} {potential} {kinetic} {pressure} {volume} {cellulea} {celluleb} {cellulec}" file EffetNb_{foldernum}_{testnum}.results screen no title “step temp enthalpy etotal pe ke press vol cella cellb cellc”

run ${iterations}

write_restart **EffetNb*{foldernum}_{testnum}.restart

unfix 3

unfix 4

fix 6 all npt temp {temperature3} {temperature3} (100*dt) iso {pression} {pression} (1000*dt)

run ${iterations}

write_restart **EffetNb*{foldernum}_{testnum}.restart

Thanks again and have a good day!