mass 1 40.078 # Ca
mass 2 12.011 # C
mass 3 15.9994 # O
mass 4 15.9994 # Ow
mass 5 1.008 # Hw
mass 6 63.550 # Cu
set type 1 charge 2.0000
set type 2 charge 1.123285
set type 3 charge -1.041095
set type 4 charge -0.847600
set type 5 charge 0.423800
set type 6 charge 0.0000
group solution type 1 2 3 4 5
group water type 4 5
# 把溶液整体上移，避免和 Cu 表面重叠
displace_atoms solution move 0.0 0.0 21.0 units box
variable a equal 3.615
# Cu(111) surface normal along z
lattice fcc ${a} orient x 1 -1 0 orient y 1 1 -2 orient z 1 1 1
variable zcu_lo equal 1.0
variable zcu_hi equal 11.5
region cu block 0 ${Lx} 0 ${Ly} ${zcu_lo} ${zcu_hi} units box
create_atoms 6 region cu
group substrate type 6
set group substrate charge 0.0
variable zfix_hi equal 6.3
region r_fixCu block 0 ${Lx} 0 ${Ly} ${zcu_lo} ${zfix_hi} units box
group fixedCu region r_fixCu
group mobile subtract all fixedCu
compute Tmobile mobile temp/com
thermo_modify temp Tmobile
fix int1 mobile nve/limit 0.005
fix lang1 mobile langevin 5.0 50.0 0.5 54321 zero yes
run 5000
unfix lang1
unfix int1
# =========================================================
# Stage 3: warm-up to 300 K
# =========================================================
fix int2 mobile nve/limit 0.005
fix lang2 mobile langevin 50.0 300.0 0.5 65432 zero yes
run 10000
unfix lang2
unfix int2
# =========================================================
# Stage 4: 300 K stabilization
# =========================================================
fix int3 mobile nve
fix lang3 mobile langevin 300.0 300.0 1.0 76543 zero yes
run 50000