Dear All!

I am a beginner in this field and I have a difficulty in writing feff.inp file for my system.

My system is CO gas adsorbed on metal (such as copper)surface and the experiment data will be taken on Cu k edge, since it is not crystalline structure, I may need to write my own feff.inp file instead of getting it from atoms.inp file. Is there anyone who knows how to create a structure for my system and how to calculate atomic coordinates of so many atoms?Or a simple structure includes only 4 atoms(2 Cu,1 C and 1 O is enough?) Then I am asking help for generating feff.inp file(especially all necessary atomic coordinates) for Cu-CO. If someone knows it, would you please give me a hand?

Thanks a million

Best Regards,