MD result analysis

Dear all,

I have a question for asking. For DFT calculation, the result is N adatom will have a strong bond with N atom on m-plane. But for MD simulation, N adatom always like to bind with Ga atom on m-plane, I have also tesed the N-N ;Ga-N; Ga-Ga interactions with respect of distance, N-N is the stongest, how to understand in MD, N prefer to form bond with Ga on surface?
Best
XJ

What potential are you using in MD, and how
are you determining it "likes to bind" in the MD?

Steve

Hi, I used Tersoff potential for GaN
For DFT calculation, the results show N adtoms have a strong interaction with N than Ga on surface, and they say N will form N-N bond.
but for MD results, all N adatoms bond with Ga on surface, not as DFT results show N like to bond with N atom on surface
I just see the results that N adatoms have bond with Ga on surface each frame.

Best
XJ

Well, maybe the parameterization of Tersoff you are using
isn't a good one for this model. I would look in the
literature to see if others have modeled these surfaces
this way.

Steve

Hi, many thanks for your reply.
GaN tersoff potential I used is from ref. J. Phys.: Condens. Matter 15 (2003) 5649–5662
the DFT calculation I compared is from ref. PHYSICAL REVIEW B 79, 241308(R) (2009)

Best
XJ