A high-quality x-ray scattering experiment on liquid water at ambient conditions

We report a new, high-quality x-ray scattering experiment on pure ambient water using a synchrotron beam line at the Advanced Light Source at Lawrence Berkeley National Laboratory. Several factors contribute to the improved quality of our intensity curves including use of a highly monochromatic source, a well-characterized polarization correction, a Compton scattering correction that includes electron correlation, and more accurate intensities using a modern charge coupled device (CCD) detector. We provide a comprehensive description of the data processing that we have used for correcting systematic errors, and we provide an estimate of our remaining random errors. The resulting error estimates of our data are smaller then the discrepancies between data sets collected in past x-ray experiments. We find that the older x-ray curves support a family of g(OO)(r)'s that exhibit a smaller first peak (similar to2.2), while the current data is better fit with a family of g(OO)(r)'s with a first peak height of 2.8, and systematic shifts in all peak positions to smaller r. (C) 2000 American Institute of Physics. [S0021-9606(00)50744-2].