# FastFourierSolver¶

class FastFourierSolver(boundary_conditions=None)

The FFT-based Poisson solver.

Parameters: boundary_conditions (list of PeriodicBoundaryCondition) – A list of shape (3,2) specifying the boundary conditions on the 6 surfaces of the unit cell for the configuration. Default: [[PeriodicBoundaryCondition()] * 2] * 3
boundaryConditions()
Returns: The boundary conditions for the solver. list of DirichletBoundaryCondition | NeumannBoundaryCondition | PeriodicBoundaryCondition | MultipoleBoundaryCondition

## Usage Examples¶

Define a FastFourierSolver with periodic boundary conditions on the 6 faces:

poisson_solver = FastFourierSolver()

calculator = LCAOCalculator(
poisson_solver=poisson_solver
)