title: Extended X-Ray absorption fine structure from hydrogen atoms in water
abstract: We report the first quantitative measurement of extended x-ray absorption fine structure (EXAFS) from hydrogen atoms. A single oscillation is observed from gaseous water consistent with the location of the covalently bonded hydrogen in H 2O. The experimental phase and amplitude of the oscillation are in excellent agreement with curved wave multiple scattering calculations for isolated water molecules. With this determination of the O-H scattering phase shift we have quantified the covalent hydrogen bond distance (0.95+/-0.03 A) in liquid water, thus demonstrating that hydrogen EXAFS can become a valuable complement to existing structural methods in chemistry and biology.
authors.affiliation: Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA.
authors.initials: KR
authors.lastname: Wilson
authors.initials: JG
authors.lastname: Tobin
authors.initials: AL
authors.lastname: Ankudinov
authors.initials: JJ
authors.lastname: Rehr
authors.initials: RJ
authors.lastname: Saykally