A spectrophotometric study of aqueous copper(I)–chloride complexes in LiCl solutions between 100 °C and 250 °C

Ab initio molecular dynamics simulation and free energy exploration of copper(I) complexation by chloride and bisulfide in hydrothermal fluids

“…In this study, it was found that Cu(I) exists as CuCl 3 2-in a 4 m chloride solution at room temperature, with the third Cl -ligand being only weakly bound; at high temperature, the linear CuCl 2 -complex predominates, even with excess chloride in the solution. This study also concluded that the tetrahedral CuCl 4 3-complex proposed for example by the UV-Vis study of Liu W et al (2002) is not stable in aqueous solution; this theoretical prediction was independently confirmed by the XAS study of Brugger et al (2007). Similar good agreement between calculated and measured speciation and complex geometries were obtained by Liu X et al (2011bLiu X et al ( , 2012 in their ab initio MD simulations of the Au(I) hydrosulfide-and Ag (I) chloride-complexes.…”

“…The hydrosulfide (mainly HS -and possibly H 2 S(aq)) and chloride (Cl -) ligands are particularly important for the transport of copper in hydrothermal fluids (e.g., Etschmann et al, 2010). A large number of solubility, in situ ultra-violet-visible (UV-Vis) spectroscopy, and XAS studies have been conducted to investigate Cu(I) speciation and retrieve thermodynamic properties for the important complexes from ambient to supercritical conditions (Archibald et al, 2002;Brugger et al, 2007;Crerar and Barnes, 1976;Etschmann et al, 2010;Fritz, 1980Fritz, , 1981Fulton et al, 2000aFulton et al, , 2000bHemley et al, 1992;Liu W et al, 2001Liu W et al, , 2002Seward, 1999, 2003;Seyfried Jr and Ding, 1993;Var'yash, 1992;Xiao et al, 1998). For Cu (I) bisulfide complexes, the current consensus is that Cu(HS) (aq) and Cu(HS) 2 -are the predominant species, with Cu(HS) 2 -becoming more important with increasing temperature .…”

“…In particular, knowledge of the geometry of the complexes places strong constraints on the range of possible species (e.g., discussion in Etschmann et al, 2011). XAS was employed to study Cu-Cl and Cu-HS/H 2 S complexing under hydrothermal conditions Etschmann et al, 2010;Fulton et al, 2000a on the ground of its stability in coordination compounds, and led to a re-interpretation of earlier UV-Vis data (e.g., Liu W et al, 2002), and greatly improved our understanding of the speciation and thermodynamic properties of Cu transport in hydrothermal fluids.…”

The controls of post-entrapment diffusion on the solubility of chalcopyrite daughter crystals in natural quartz-hosted fluid inclusions

“…van der Laan et al, 1992;Rickard and Cowper, 1994;Pearce et al, 2006) and the predominant oxidation state of Fe in solution at elevated temperatures and a range of salinities is likely to be +2 (e.g. Seyfried and Ding, 1993;Liu et al, 2002). Given this, and assuming the proposed complexes of Cu in solution noted above, the likely equilibria that govern the solubility of chalcopyrite in fluid inclusions are: …”

MINQ8: general definite and bound constrained indefinite quadratic programming

“…Applications of MINQ5 to bound constrained quadratic programs include the calculation of the formation constants for copper(I)-chloride complexes [19], subpixel land cover mapping [3], an optimal control model of redundant muscles in step-tracking wrist movements [10], entropy estimation for high-dimensional finite-accuracy data [16], finding the best code to represent a speech signal [23], the calculation of a nonnegative sparsity induced similarity measure for cluster analysis of spam images [7], a method for calibrating the scores of biased reviewers [22], a model for the braking behavior of industrial robots [2], and finding the filter coefficients for a filtering technique to denoise the far-field pattern in the presence of noise [21]. Moreover, many nonlinear optimization techniques are based on solving auxiliary quadratic problems [6,14,18,24,25].…”