Frank: Please keep in mind that the "rotation" in the Lorentz transform is hyperbolic, not circular.
A circular rotation has the form | cos(theta) sin(theta) | | -sin(theta) cos(theta) | and it maps circles centered on the origin into other circles centered on the origin. It appears to me that when you talk about a molecule or orbital being twisted on the time axis, you may be thinking of a *circular* rotation carrying one end of the object "forward" and the other end "backward". A hyperbolic "rotation" is rather different. It has the form | cosh(u) sinh(u) | | sinh(u) cosh(u) | It maps hyperbolas centered on the origin to other hyperbolas, but it generally makes dogfood out of circles. In particular ordinary lengths of the form x^2 + y^2 are not preserved; instead, the interval x^2 - y^2 is preserved. For very small rotations, on the other hand, both circular and hyperbolic rotations will push one end of a rod "forward" and the other "backward" if we rotate the rod by a tiny amount, and perhaps that's all you need. But if the rotations are more than tiny, the actions are quite different.
