### This lammps-script was used for calculation of melting line (Fe and Al) in work ### Starikov S.V., Stegailov V.V. Premelting of iron and aluminum: implication for ### high-pressure melting curve measurements // Phys. Rev. B., 2009, V. 80, P. 220104(R) ### ### calculation of melting temperature of aluminum at low pressure dimension 3 boundary p p p units metal atom_style atomic neighbor 0.3 bin neigh_modify every 20 delay 0 check no ### T0 - initial temperatura of calculation ### Given temperature \${realT0} devided to 2.2 must be some bigger than expected melting temperature Tm variable T0 equal 1070 variable realT0 equal \${T0}*2.2 variable Tm equal 950 ### x - number of crystal cell in x-direction ### a - lattice constant ### l - size of calculation cell in x-direction variable x equal 45 variable a equal 4.05 variable l equal \$x*\$a lattice fcc \$a #lattice hcp \$a #lattice bcc \$a region box block 0 \$x 0 15 0 15 create_box 1 box create_atoms 1 box mass 1 26.98 pair_style eam/alloy pair_coeff * * /home/user/alcu.foiles.eam.alloy.txt Al velocity all create \${realT0} 481516 dump id all cfg 2500 /home/user/dump/al_melt_1.*.cfg id type xs ys zs dump_modify id element Al timestep 0.0005 thermo_style custom step temp etotal pe press pxx pyy pzz vol thermo 30 ### Equilibration with or without Langevin thermostat fix 1 all nve #fix 2 all langevin \${T0} \${T0} 20 481516 run 3000 unfix 1 #unfix 2 lattice sc 1.00 variable d1 equal \$l*0.225 variable d2 equal \$l*0.275 region del block \${d1} \${d2} -10 100 -10 100 delete_atoms region del variable h equal \$l*0.5 region liquid block -10 \$h -10 100 -10 100 group liquid region liquid ### Creation of two-phase system fix 3 liquid nve run 50000 unfix 3 velocity all create \${Tm} 481516 fix 4 all nve run 50000 unfix 4 #write_restart /home/user/equilibrium.restart ### main calculation variable len equal \$l*0.95 region twophase block 5 \${len} -10 100 -10 100 group twophase region twophase fix 5 twophase nve run 100000 #write_restart /home/user/end.restart ### The analysis about accuracy of the initial estimation of melting temperature Tm can be perfermed by change of temperature, ### visually observation of phase interface or on the basis of parameter of order [Phys.Rev.B., 2009, V.80, P.220104(R)]