Diffusion foctor of Li in LiFePO4

Dear Gulp users
I am new user of GULP (materials studio 8) and I would like to help me to determine the diffusion factor of Li in LiFePO4, I use the BVS forcefield (Stefan Adams).
I have problem in the parametres of NPT simulation,
how much pressure I applied
the thermostat parameter
the barostat parametre
thank you

Dear Youssef,
To learn about computing diffusion coefficients (I’m assuming this is what you mean) then I would recommend reading one of the two standard texts on MD - Allen & Tildesley or Frenkel & Smit. This will also help to understand how to select thermostats & barostats to achieve a reasonable ensemble.
It should be noted that GULP is more focused on lattice dynamics than molecular dynamics & so for materials with slow diffusion on an MD timescale it would make more sense to compute the barriers to diffusion and use transition state theory to obtain the rates of hopping between minima. The overall diffusion can then be determine by a higher level approach on top of this information, such as kinetic Monte Carlo.
Hope that helps,

Julian

Dear Julian
Thank you very much