First-principles study of sulfur isotope fractionation in sulfides
Liu, Shanqi; Li, Yongbing; Tian, Huiquan; Yang, Junli; Liu, Jianming; Shi, Yaolin
European Journal of Mineralogy Volume 26 Number 6 (2014), p. 717 - 725
published: Dec 1, 2014
ArtNo. ESP147052606003, Price: 29.00 €
Isotope fractionation parameters for sulfur have been calculated using first-principles methods based on density-functional perturbation theory for sphalerite, galena, alabandite, greenockite and cinnabar in the temperature range of 0–1000 °C. For comparison, the 103 ln α value between sphalerite and galena, which appears to be well determined, is also calculated, and a good agreement between this calculation and other results is found. The calculations show that the order of heavy isotope enrichment is sphalerite > cinnabar > greenockite > alabandite > galena. The reduced partition function ratios of 33S/32S, 36S/32S in the temperature range of 0–1000 °C are also calculated, and there exists a fixed proportion relation between sulfur isotope 32S, 33S, 34S and 36S in the calculated five sulfides, which can be expressed as δ34 S = 1.940 δ33 S and δ36 S = 1.891 δ34 S, in agreement with previously published relationships.