Respected lammps users，according to the literature found, I used FIX/EFIELD to simulate the conduction of metal wires, giving each atom an electric charge during the simulation. However, when I checked the results after the run, I found that each atom remained stationary under the action of the electric field. I want to know what I missed in the process that led to this. I hope to get your advice.
Below is my lammps script：
boundary p p p
lattice fcc 3.615
region box block 0 10 0 10 0 20
create_box 1 box
create_atoms 1 box
mass 1 63.55
set type 1 charge 1.0
pair_coeff * * Cu_u3.eam
neighbor 2.0 bin
neigh_modify every 1 delay 0 check yes
velocity all create 300 12345
fix 1 all efield 0.0 0.0 1.0
thermo_style custom step temp press pe ke etotal
dump 1 all custom 1000 dd.xyz id type x y z
This seems very unlikely to give useful information about real electrical conductivity, since this has very little relationship to the Drude model of conduction (which is more than a hundred years old).
More importantly, the script you posted does not seem to have an integrator (such as
fix nvt) and so your particles do not move.
Conduction in metals is carried by electrons, not atoms and since the EAM model you are using is a classical model, there are no electrons present.
What you do with fix efield is the same as if you add a constant force to each atom. There is nothing that can be learned from that.
That’s why, and I’ve ignored that, and thank you from the bottom of my heart for pointing it out.
Thank you for your reply! It may be that I still have a unclear understanding of the conductive process, this is an attempt to simulate the MD of conductivity, and I will continue to study this aspect in the future. Do you have any suggestions for this? Please give me some pointers, I would appreciate it.
Sorry, this forum is not a replacement for talking to your adviser and such fundamental issues regarding your research are a topic for a chat with your adviser. My suspicion is that you have misunderstood something.