Dear Steve, In your 2002 paper on the perturbation theory with shifting material boundaries, you formulate the problem in terms of parallel and normal fields. I am hoping that I can follow that procedure to do some perturbation analysis based on MPB result. Then the question is how I can determine the normal vector as well as epsilon_parallel and epsilon_normal for each grid point. The most direct way is of course, to use the same spherical-quadrature method as implemented in MPB. But I am wondering if there is some simpler way for me to extract such information. I have tried to do the svd decompostion on the output epsilon tensor at each grid point, but the problem is that I don't know how to automatically decide which diagonal element corresponds to the parallel epsilon and which corresponds to the normal epsilon. Do you have any suggestions on this?
Thanks a lot. Regards, Minghui Han _______________________________________________ mpb-discuss mailing list mpb-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
