Zinc complexation in hydrothermal chloride brines: Results from ab initio molecular dynamics calculations

DJ Harris*, JP Brodholt, DM Sherman

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

26 Citations (Scopus)

Abstract

We determined the coordination environment of Zn(2+) in aqueous Cl(-) brines at 25 degreesC and 300 degreesC using ab initio molecular dynamics simulations. The ZnCl(+) and ZnCl(2) complexes exist as pseudo-octahedral ZnCl(m)(H(2)O)(6-m) clusters at 25 degreesC but occur as pseudo-tetrahedral ZnCl(m)(H(2)O)(4-m) clusters at 300 degreesC. The ZnCl(3)(-) complex occurs as the pseudo-tetrahedral ZnCl(3)(H(2)O)(-) cluster at 25 and 300 degreesC. The tetrahedral ZnCl(4)(2-) complex, however, is the dominant Zn-Cl complex at 25 degreesC, at least in highly concentrated (7.4 m) Cl(-) brines. The change in hydration number with temperature for the ZnCl(+) and ZnCl(2) complexes will complicate extrapolations of solvation energies to hydrothermal conditions using a Born-model-based equation of state.

Original languageEnglish
Pages (from-to)1050-1054
Number of pages5
JournalJournal of Physical Chemistry A
Volume107
Issue number7
DOIs
Publication statusPublished - 20 Feb 2003

Keywords

  • PARTIAL MOLAL PROPERTIES
  • AQUEOUS-SOLUTION
  • HIGH-PRESSURES
  • 350-DEGREES-C
  • TEMPERATURES
  • STABILITIES
  • STANDARD
  • RAMAN

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