Please post your questions to the LAMMPs mailing list.

Whether it is close to the experimental value is not the right question to ask. Instead you should ask, is it close to the known value for this potential. If not, examine the LAMMPS log file to see if the calculation proceeeded correctly. In particular, make sure the minimization converges to the correct initial state, and also that it converges after each deformation.

Aidan

Yes, you are right. The known values of this potential is bulk modulus B. Actually this potential indeed returns close value to the bulk modulus,

2012/4/4 Thompson, Aidan <[email protected]>

In that case, why are you looking at C11? You should first see if you get the known value of B.

I don’t know how to get B directly, so I calculate C11 and C12, then transfering values to B.

2012/4/4 Thompson, Aidan <[email protected]>

Hi,

I don’t know how to get B directly, so I calculate C11 and C12, then transfering values to B.

Bulk modulus is a reciprocal of isothermal compressibility, the latter can be extracted from the variation of volume as a function of pressure.

Hope this help.

christopher