Choice of epsilon1

[yaz...@gmail.com]

Hi Mit

May I know where are the Epsilon1 values in the model_scaling input obtained from? I have a doped monolayer MoSe2, and my understanding is to take epsilon_a1 and a2 from a pristine Monolayer MoSe2 to simulate the dielectric constant when doping approaches 0% and to take epsilon_a3 from the bulk MoSe2 to avoid the deviation in dielectric constant caused by different vacuum heights. However, may I double check with you if this is indeed what the code want or it wants something else, like, taking Epsilon1 values from doped Monolayer MoSe2 6x6x1 supercell with cell dimensions of a x a x a ? (I'm following the example and am using 6x6x1 cells for the DFT calculations needed by COFFEE.)

Best wishes

Yaze

[Mit Naik]

Dear Yaze,

The model epsilon values are all obtained from pristine calculations. The epsilon_a1 and epsilon_a2 obtained from DFPT will also vary with the amount of vacuum. Please follow section III A in reference PhysRevB.89.205417 to obtain the converged value for in-plane and out-of-plane epsilon. 

Best,

Mit 

[yaz...@gmail.com]

Hi Mit

Thanks a lot! This answers everything.

Best wishes

Yaze