Vashishta Potential vs Al.eam.alloy potential

Dear All,

I am trying to find out solid Al2O3 thermal conductivity at room temperature using GREEN KUBO method. I had built a solid crystal of Al2O3 (1500 molecules) using packmol and once used Vashishta potential and in another code used EAM potential to find the difference in the thermal conductivity with both the potential. When I have used EAM potential, the code runs well although I didn’t get the correct thermal conductivity value. But when I ran the code with Vashishta potential I got this error “Lost atoms: original 7500 current 3 (…/thermo.cpp:398)” even when I lowered the time step from 0.0001 to 0.000001 in metal units. Please suggest me what should do I change while using Vashishta potential, as this potential best describes the thermal properties of Al2O3.

I did minimization and then equilibrate with NVT followed by NVE and finally Green Kubo lammps code to determine thermal conductivity. Thanks!

Dear All,

I am trying to find out solid Al2O3 thermal conductivity at room temperature using GREEN KUBO method. I had built a solid crystal of Al2O3 (1500 molecules) using packmol and once used Vashishta potential and in another code used EAM potential to find the difference in the thermal conductivity with both the potential. When I have used EAM potential, the code runs well although I didn’t get the correct thermal conductivity value. But when I ran the code with Vashishta potential I got this error “Lost atoms: original 7500 current 3 (…/thermo.cpp:398)” even when I lowered the time step from 0.0001 to 0.000001 in metal units. Please suggest me what should do I change while using Vashishta potential, as this potential best describes the thermal properties of Al2O3.

I did minimization and then equilibrate with NVT followed by NVE and finally Green Kubo lammps code to determine thermal conductivity. Thanks!

Regards,
Zeeshan Ahmed
PhD Student (Mechanical Engineering)

The GK method is simply a diagnostic calculation which does

affect the dyanmics. So I think you are really saying

you cannot run NVE for a long period of time with the

Vashishita potential on the system you’ve defined.

I suggest you verify that you can reproduce values for

A22O3 in the literature using the potential and a
simple geometry, e.g. a perfect crystal.
There is probably something wrong with

the system you are defining.

Steve

Thank you for the clarification.