Posted: Mar 09, 2010 11:27 pm
magetoo wrote:Are there any plausible models that incorporate all three distances? There has to have been some that came up between 1938 and the later findings, I would think.
Some people think it's rings or clusters or chains. The tetrahedral crowd has been predominate for a long time because, frankly, the O-O coordination number consistently comes out close to four. But it would be an average, so who knows.
X-ray absorption spectroscopy has shown a possible asymmetry in water structure (strong and weak hydrogen bonds), and when it got modeled, about the most that could be said is that neither x-ray or neutron diffraction were sensitive enough to see a difference between symmetric and asymmetric models. This might possibly explain why the many people who've measured water on conventional diffractometers haven't seen what these guys in the new study have seen. The radial O-O partial normally takes a dip around 3.5A, but those peaks on either side are pretty damned broad...
Water has always been interesting and controversial, and its researchers are a rough crowd. So for me it's
