Self-adjoint extensions of the Laplace operator with respect to electric and magnetic boundary conditions

Systems of the type {$\text{A, KJ, 2iK1, I}$} are studied where $\text{J  J1}$ is unitary and $\text{KJK1 }\text{Im}\text{A}$. A complete realization theory as well as state space isomorphism theorem are given. Coupling problems are considered.