[lammps-users] problem with the stability of gold structure

Hello everybody,

I’m trying to simulate a gold nanowire and I have a weird problem with the stability of the structure. The initial structure starts to expand very quickly without any load applied. It seems it is because of very high internal pressure. I believe that there is something wrong with defining the structure with the lattice parameter of 4.08 that produces this high internal pressure. Because when I change the lattice parameter to 2A, the structure is stable and it doesn’t expand. I tried to use different potentials and different geometries and still got the same results. I don’t have this problem with any other potentials e.g. for Cu and Ni.

Has anybody worked with gold potentials and have had similar experiences? Does anybody have any suggestions of the source of my problem?

Thank you,


2 vs 4 Angs is huge difference. Something must be wrong
about the way you are generating your structure or the potential
you are using.



What potential are you using? I have done some simulations of gold nanowires and I found phase transformation from fcc to bct happens when the size of gold nanowires is very tiny. But your description of lattice shrinkage from 4.08 A to 2 A is not what I found. Did you check the lattice structure of the relaxed configuration?

FYI, our work published recently in the following paper:

Discrete plasticity in sub-10-nm-sized gold crystals # He Zheng,Ajing Cao,Christopher R. Weinberger, Jian Yu Huang,Kui Du,Jianbo Wang,Yanyun Ma,Younan Xia & Scott X. MaoNature Communications 1, Article number:144 | DOI:10.1038/ncomms1149



Dear Ajing,

Thank you so much for your reply. Sorry for my late response. I haven’t seen your email so far because of email filtering . I had made a silly mistake on defining the structure. Now my structure works fine. I think I also see some phase transformations but am not sure if it really is a phase transformation or other processes. Im sure your paper will be very informative for me since Im doing very similar simulations.

Thanks again for your interest,