Suitable Tersoff Potential File for CNT Simulation

Hello all,

I noticed that Tersoff potential file available in Lammps package (LAMMPS 64-bit 20170127) is not going well with CNT.

Can somebody pls forward me recent/suitable potential file for CNT?

Thanks!,

Rajni Chahal

Hello all,

I noticed that Tersoff potential file available in Lammps package (LAMMPS
64-bit 20170127) is not going well with CNT.

​such blanket statements are not very scientific.

for starters, there are 6 (six!) different Tersoff potential files bundled
with LAMMPS that include parameters for carbon. have you tried them all?
​how do you determine, that they are "not going well"? and what does "not
going well" mean?
​how do you know, that the problem is not caused by something else in your
input?​

Can somebody pls forward me recent/suitable potential file for CNT?

​sorry, but that is not how things work. if you believe that there must be
better potentials available, you need to first do a proper literature
search and identify publications that describe successful simulations
similar to what you want to do, then you can compare the potentials or
parameters in those studies with what is available with LAMMPS. if the
parameters are not available in LAMMPS, you can write a new potential file
based on the existing ones and what is referenced in the publication.​

​but before you go this far, i strongly recommend to review your simulation
input instead.

axel.​

Hello Axel,

I noticed that Tersoff potential file available in Lammps package (LAMMPS 64-bit 20170127) is not going well with CNT.

such blanket statements are not very scientific.

for starters, there are 6 (six!) different Tersoff potential files bundled with LAMMPS that include parameters for carbon. have you tried them all? how do you determine, that they are “not going well”? and what does “not going well” mean?
how do you know, that the problem is not caused by something else in your input?

I think it is “not going well” because it is giving me a large strain to failure, which is much higher than that reported in literature.

Can somebody pls forward me recent/suitable potential file for CNT?

sorry, but that is not how things work. if you believe that there must be better potentials available, you need to first do a proper literature search and identify publications that describe successful simulations similar to what you want to do, then you can compare the potentials or parameters in those studies with what is available with LAMMPS. if the parameters are not available in LAMMPS, you can write a new potential file based on the existing ones and what is referenced in the publication.

but before you go this far, i strongly recommend to review your simulation input instead.

I got your point. I shall look for updated potential parameters in literature, if potential will be the problem here.

Thanks a lot!,
Rajni Chahal

Hello Axel,

I noticed that Tersoff potential file available in Lammps package (LAMMPS
64-bit 20170127) is not going well with CNT.

such blanket statements are not very scientific.

for starters, there are 6 (six!) different Tersoff potential files bundled
with LAMMPS that include parameters for carbon. have you tried them all?
how do you determine, that they are "not going well"? and what does "not
going well" mean?
how do you know, that the problem is not caused by something else in your
input?

I think it is "not going well" because it is giving me a large strain to
failure, which is much higher than that reported in literature.

​did you use the same tersoff potential as was used in your literature
reference? are you using the same strain rate?​

​axel.​