Does this POL card

setting mean that the electric vector is along the z/c axis of the crystal axis?

Not quite. FEFF doesn't really know about crystal symmetry. The coordinates in the POLARIZATION card are the same as those in the feff.inp file under the ATOMS card. If the c axis of the crystal happens to be along the z direction, then POLARIZATION 0 0 1 sets the electric field vector along the c axis. You will have to look at the coordinates in the feff.inp to figure out which direction the c axis is. I may be wrong, but I think atoms/webatoms puts the c-axis in the z direction by default. Cheers, Josh Kas

I did read the Feff manual and the POL card but I am still confused how to relate these to the crystal structure and orientation.

Thank you all in advance,

-- Chris Patridge PhD. Candidate Dept. of Chemistry SUNY University at Buffalo Buffalo, NY 14260 Contact: 315-529-0501