Band edges of periodic Schrödinger operators are generically isolated and nondegenerate

For periodic Schrödinger operators $H_V=-Δ+V$ with bounded real-valued potentials on $\mathbb R^d$ with $d\ge2$, we show that for generic potentials, each endpoint of every spectral gap is attained by a single Bloch band at only finitely many quasimomenta, and has a nondegenerate Hessian at every at