Hi Fiona, An experimental standard is a spectrum of a known material (the term is also often used for the known material itself, in addition to its spectrum). If you use Athena to do a linear combination fit, you are most commonly using experimental standards to do it. A theoretical standard is a theoretically simulated spectrum of some structure. Thus, the theoretical standard is not the crystallographic data itself, although that data can serve as a basis for generating a theoretical standard using software such as FEFF. --Scott Calvin Sarah Lawrence College On Jan 4, 2010, at 7:16 PM, Fiona R. Kizewski wrote:
Dear all, Can somebody please explain to me what is theoretical standard and what is experimental standard. My understanding of theoretical standard is the crystallographic data. However, it is first time I heard experimental standard. Thanks