Ammonium hydroxide (NH4+…OH–) can be characterised quantum mechanically when stabilised by water bridges connecting the ion-pairs. It is a small step from there to hydronium hydroxide, or H3O+…OH–. The measured concentrations [H3O+] ≡ [OH–] give rise of course to the well-known pH 7 of pure water, and converting this ionization constant to a free energy indicates that the solvated ion-pair must be some ~19.1 kcal/mol higher in free energy than water itself.♣ So can a quantum calculation reproduce pH7 for water?
Publishing embargoes seem a relatively new phenomenon, probably starting in areas of science when the data produced for a scientific article was considered more valuable than the narrative of that article. However, the concept of the embargo seems to be spreading to cover other aspects of publishing, and I came across one recently which appears to take such embargoes into new and uncharted territory.
Augmented reality, a superset if you like of virtual reality (VR), has really been hitting the headlines recently. Like 3D TV, its been a long time coming! Since ~1994 or earlier, there have been explorations of how molecular models can be transferred from actual reality to virtual reality using conventional computers (as opposed to highly specialised ones). It was around then that a combination of software (Rasmol) and hardware (Silicon Graphics, and then soon after standard personal computers with standard graphics cards) became capable of such manipulations. VRML (virtual reality modelling language) also proved something of a false start‡ So have things changed?
At the precise moment I write this, there is information about 108,230,950 organic and inorganic chemical substances from the World's disclosed chemistry. So it was with a sense of curiosity that I came across this article in the American Mineralogist entitled "Earth’s “missing” minerals" (the first in a series of articles apparently planned on the topic of the missing ones). The abstract is particularly interesting and whilst I encourage you to go read the article itself, I will quote some eye-catching observations from just this abstract:
- R.M. Hazen, G. Hystad, R.T. Downs, J.J. Golden, A.J. Pires, and E.S. Grew, "Earth’s “missing” minerals", American Mineralogist, vol. 100, pp. 2344-2347, 2015. http://dx.doi.org/10.2138/am-2015-5417