ffsim.dims¶ ffsim.dims(norb, nelec)[source]¶ Get the dimensions of the FCI space. Parameters: norb (int) – The number of spatial orbitals. nelec (tuple[int, int]) – The number of alpha and beta electrons. Return type: tuple[int, int] Returns: A pair of integers (dim_a, dim_b) representing the dimensions of the alpha- and beta- FCI space.