Whittaker-Hill势Q 2 x = 1 2 h 2 cos 4 x + 4 h¼Sch cos 2 x $$ {Q} _2（x）= \ frac {1} {2} {h } ^ 2 \ cos \ 4x + 4h \ mu \ cos \ 2x $$和周期复数电势Q 1 x = 1 4 h 2 e – 4 ix + 2 h 2 cos 2 x $$ {Q} _1（ x）= \ frac {1} {4} {h} ^ 2 {\ mathrm {e}} ^ {\ hbox {-} 4ix}