QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: DSarkar on March 23, 2016, 07:28

Title: Boundary conditions
Post by: DSarkar on March 23, 2016, 07:28

Hi,

How do I know if periodic boundary conditions are applied to my simulation structure? And how would I change the boundary conditions?

Regards,

Debarghya

Title: Re: Boundary conditions
Post by: Jess Wellendorff on March 23, 2016, 09:36

The boundary conditions are implemented on the Poisson Solver, see attached PNG.

The default Poisson Solver for a bulk configuration is FFT with periodic BCs on all sides of the supercell. If no Poisson Solver is specified in the script, the default one is used.

For device configurations, the default BCs on the electrodes are also fully periodic:

Code

left_electrode_poisson_solver = FastFourier2DSolver(
    boundary_conditions=[[PeriodicBoundaryCondition(),PeriodicBoundaryCondition()],
                         [PeriodicBoundaryCondition(),PeriodicBoundaryCondition()],
                         [PeriodicBoundaryCondition(),PeriodicBoundaryCondition()]]
    )

Title: Re: Boundary conditions
Post by: DSarkar on March 24, 2016, 08:30

Thanks for the clarification, Jess.