We consider a Schrödinger differential expression L = Δ A + q on a complete Riemannian manifold ( M , g ) with metric g , where Δ A is the magnetic Laplacian on M and q ≥ 0 is a locally square integrable function on M . In the terminology of W.N. Everitt and M. Giertz, the differential expression L is said to be separated in L 2 ( M ) if for all u ∈ L 2 ( M ) such that L u ∈ L 2 ( M ) , we have q u ∈ L 2 ( M ) . We give sufficient conditions for L to be separated in L 2 ( M ) .