AIREBO POTENTIAL rcmin and rcmax

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1

Hello users,

I am working with carbon nanotubes. I am using AIREBO potential for my simulations.

can any one explain me what is the significance of values against rcmin_CC and rcmax_CC.

I had understood in a way that rcmax_CC represents the covalent bond breaking length between C-C.

I have a doubt in rcmin_CC, whether its equilibrium bond length between C-C or something else. (I red bond length of C-C is 0.142nm somewhere.).

If i change both values its reflecting different nature in my simulations.

Kindly please help me out. If possible advise me some sources for learn about this.

Thanks

TK

2

Please read the AIREBO paper (Stuart JCP 2000) for more details, or simpler the Tersoff (Tersoff 1988 PRB) potential on meanings of inner and outer cutoffs.

Ray

3

Thanks for your reply ray.

Can please tell me exactly what is the purpose of inner and outer cutoff instead of having only one cutoff.

If possible can u please explain me with some examples.

4

Look at the papers I suggested to you.

Ray

5

Thanks for your reply ray.
Can please tell me exactly what is the purpose of inner and outer cutoff
instead of having only one cutoff.
If possible can u please explain me with some examples.

please note that this has nothing to do with LAMMPS but is a pure
science question. if you want to have ray (or somebody else) act as
your adviser or consultant, you have to offer suitable compensation
for his efforts. this mailing list is no replacement for doing
bypassing doing what is essentially your homework.

axel.

p.s.: i *strongly* recommend against modifying cutoffs when you don't
even understand the basic motivations behind them. in general complex
potentials like airebo are parameterized as a whole and modifying a
single parameter without readjusting everything else, can destroy the
very delicate balance between them. even if certain parameters are
motivated by simple concepts, the impact of changing them is rarely
that simple.