[Wien] How to compare OPTIC results and EELS experiments?

[Ruijuan Xiao]

Dear all,

I have a question about the comparison between OPTIC calculated results and EELS experiments.The calculated loss functions include several components(e.g. eloss_xx,eloss_yy,eloss_zz).And in the electron energy loss spectrum(EELS), the direction of incident electron can be adjusted.I wonder the relationship between the eloss_xx(or yy or zz) and the direction of incident electron. Does it mean the calculated eloss_xx corrsponds to the experiment in which the incident electron are perpendicular to the x direction? Another question is whether the convergence angle is set to zero in the calculation? Is there any reference about this? 

I am looking forward to your reply. Thank you for any of your help.

Best regards,

Sincerely,
Ruijuan Xiao
Institute of Physics,
Chinese Academy of Sciences