Hi Kristine, Matt, I just remembered a discussion on the (meanwhile rather inactive?!) feffusers list concerning ELLIPTICITY and thought I should quote that.
Oh... one more question... I haven't been using the ellipticity card in the feff.inp file, even though I've been using "POLARIZATION 1 0 0"... is this OK?
Yes, the ellipticity card is for describing polarizations that are not linear, such as for magnetic circular dichroism. For your surface EXAFS experiments at APS 5-ID, the x-rays were highly linearly polarized.
As of 2002-04-25 Alex Ankudinov wrote: - - - - snip - - - - ELLIPTICITY specifies the direction of incoming x-ray and the ratio of intensities along two perpendicular directions, one of which is specified by POLARIZATION card and the other is found automatically. ELLIPTICITY is not intended to be used for circular polarized light. One has to use XMCD card, which assumes 100% circular polarized light. - - - - snip - - - - Best, Peter -- -------------------------------------------------------------- Peter Pfalzer Universitaet Augsburg Tel: +49-821-598-3215 Lehrstuhl fuer Experimentalphysik II Fax: +49-821-598-3411 Universitaetsstr. 1 D-86135 Augsburg Germany Peter.Pfalzer@physik.uni-augsburg.de http://www.physik.uni-augsburg.de/exp2 --------------------------------------------------------------