[Ifeffit] Query: abnormal FT-EXAFS peak at ~1.1A

Hello! I faced an issue with fitting of FT-EXAFS data (Rh@zeolite) with Artemis. There is one distinct peak located at ~1.1 angstron. The intensity is comparable to the nearby peak of Rh-O scattering. I wonder the peak (~1.1A) is a real peak or just noise. Raw data is enclosed. Another question is why S02 can be negative in data fitting with Artemis. Cheers, Huaming