How to tell whether the potential is reasonable

Dear all users,

Sorry to bother you. I am learning to do some molecular dynamics calculations of Pt using lammps. But I have some difficulties with EAM potentials.
My question is about the Pt eam potential (My potential is generated by H. W. Sheng, PHYSICAL REVIEW B 83, 134118 (2011), ) :

I want to do some MD about dislocations and twins in Pt nano sheet. Before the calculation, I tried to calculte the stacking fault energys (SFE) of Pt to ensure that the potential is good enough.

But my results are not so consistent with expirements and DFT results. For example, the SFE in my calculation is about 118 mJ/m2, and the unstable SFE is about 341 mJ/m2. But the value of expirements and DFT are more bigger (for example, 330 mJ/m2 for SFE and 422mJ/m2 for unstable SFE in PHYSICAL REVIEW B 69, 224104 (2004) ).

In my opinion, the differcence are a bit too large. I am not sure whether the difference can be tolerated.

So I need some advices that whether the EAM potential can describe the Pt dislocations reasonably. Can I use this potential to do my MD calculations ?
Do you have any other potentials can describe the Pt interactions more accurately?

Looking forward to your reply.


Nianke Chen

Hi Nianke,

I just joined into LAMMPS and did some similar work of FCC metals recently. Have you relaxed you model before displacing the atoms? Other potentials for Pt can be found hrere Hope this useful.