YIN Xin-ya1，LIU Qi2
(1. Guizhou Minzu University, Guiyang 550025, China;
2. State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China)
Abstract：Density functional method is used to simulate effects from cations for calculating isotope fractionation factor between B(OH)3 and B(OH)4- in seawater. “Water-droplet” configuration based on molecular cluster model is chosen for simulating seawater environment, and up to 12 water molecules are used to surround the interested molecules in “water-droplets”. This study shows equilibrium isotope fractionation factor between B(OH)3 and B(OH)4- is 1.031 in seawater at 25˚C, which is similar to the fractionation factor in pure water. Our results show that there may be improprieties in previous experimental observation of boron isotope fractionation in solution, and provide theoretical constrains for better constructing paleo-environments by boron isotope proxy and better measuring equilibrated boron isotope fractionation in solution.
Keywords：boron isotope; equilibrium isotope fractionation; quantum chemical calculation; cations; seawater
Email: liu.qi@ymail.com
ACTA MINERALOGICA SINICA Vol. 35, No. 3, 2015, Page 379-383
