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ABSTRACT Lafossaite, idealized formula TlCl, is cubic, space group P-m3m (by analogy with the synthetic inorganic equivalent) with unit-cell parameter refined from powder data: a = 3.8756(3) [Angstrom], V = [...]

Fluid-phase stability relations combined with thermodynamic modeling using fluid-inclusion analyses and new gold-solubility experiments lead to an integrated geological interpretation linking epithermal gold mineralization and porphyry-style ore formation to the cooling of hydrous magma chambers. The essential chemical requirement for gold transport to low temperatures is an initial excess of sulfide over Fe in the magmatic fluid, which is best achieved by condensing out Fe-rich brine from a buoyant, low- to medium-salinity vapor enriched in volatile S. This vapor can contract directly to an aqueous liquid, by cooling at elevated pressure above the critical curve of the salt-water fluid system. Physical and chemical conditions are matched when magmatic fluid is released through a gradually downward-retracting interface of crystallizing magma beneath a porphyry stock, predicting the consistent zoning and overprinting relations of alteration and mineralization observed in magmatic hydrothermal systems. Keywords: gold solubility, magmatic deposits, vapor; brine, epithetreal, porphyry, thermodynamic modeling.

The water-dimer formation and its encapsulation into D2(22)-C84and D2d(23)-C84fullerenes is evaluated. The water-dimer populations are computed using the potential-energy change from the G3 theory and anharmonic partition functions from the MP2/AUG-cc-pVQZ approach. The encapsulation energetics is treated at the M06-2X/6-31++G** level and it is found that the water-dimer storage in C84is attractive, yielding an energy gain of more than 10 kcal mol−1. This substantial encapsulation energy together with the computed temperature increase of the water-dimer population in the saturated steam suggests that the (H2O)2@C84endohedrals could be produced in a high-temperature/high-pressure approach similarly to encapsulation of rare gases in fullerenes. [ABSTRACT FROM PUBLISHER]