@article{fdi:010064674,
  title = {{E}quilibrium magnesium isotope fractionation between aqueous {M}g2+ and carbonate minerals : insights from path integral molecular dynamics},
  author = {{P}inilla, {C}. and {B}lanchard, {M}. and {B}alan, {E}tienne and {N}atarajan, {S}. {K}. and {V}uilleumier, {R}. and {M}auri, {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he theoretical determination of the isotopic fractionation between an aqueous solution and a mineral is of utmost importance in {E}arth sciences. {W}hile for crystals, it is well established that equilibrium isotopic fractionation factors can be calculated using a statistical thermodynamic approach based on the vibrational properties, several theoretical methods are currently used to model ions in aqueous solution. {I}n this work, we present a systematic study to determine the reduced partition function ratio (beta-factor) of aqueous {M}g2+ using several levels of theory within the simulations. {I}n particular, using an empirical force field, we compare and discuss the performance of the exact results obtained from path integral molecular dynamics ({PIMD}) simulations, with respect to the more traditional methods based on vibrational properties and the cluster approximation. {T}he results show the importance of including configurational disorder for the estimation of the equilibrium isotope fractionation factor. {W}e also show that using the vibrational frequencies computed from snapshots taken from equilibrated classical molecular dynamics represents a good approximation for the study of aqueous ions. {B}ased on these conclusions, the beta-factor of aqueous {M}g2+ have been estimated from a {C}ar-{P}arrinello molecular dynamics ({CPMD}) simulation with an ab initio force field, and combined with the beta-factors of carbonate minerals (magnesite, dolomite, calcite and aragonite). {M}g beta-factor of {M}g-bearing aragonite, calculated here for the first time, displays a lower value than the three other carbonate minerals. {T}his is explained by a strong distortion of the cationic site leading to a decrease of the coordination number during {C}a-{M}g substitution. {O}verall, the equilibrium magnesium isotope fractionation factors between aqueous {M}g2+ and carbonate minerals that derive from this methodological study support the previous theoretical results obtained from embedded cluster models.},
  keywords = {},
  booktitle = {},
  journal = {{G}eochimica et {C}osmochimica {A}cta},
  volume = {163},
  numero = {},
  pages = {126--139},
  ISSN = {0016-7037},
  year = {2015},
  DOI = {10.1016/j.gca.2015.04.008},
  URL = {https://www.documentation.ird.fr/hor/fdi:010064674},
}