Recent content by pascal

Thanks, Adam. That does make sense. The only question I have now is which of the indices are contravariant, and which are covariant? I've looked through MANY NLO books and cannot find any resource that addresses this question.

I'm working on a calculation of the second hyperpolarizability "\beta" of a compound with D(3) symmetry, and I am trying to figure out how the tensor \beta transforms under a coordinate rotation about the z axis (the three-fold symmetry axis). I know that if we have two bases x and x' with a...