@article{fdi:010061974,
  title = {{T}heoretical study of the local charge compensation and spectroscopic properties of {B}-type carbonate defects in apatite},
  author = {{Y}i, {H}. {H}. and {B}alan, {E}tienne and {G}ervais, {C}. and {S}egalen, {L}. and {B}lanchard, {M}. and {L}azzeri, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he structure and spectroscopic properties of selected models of {B}-type carbonate defects in apatite locally compensated by fluoride or hydroxyl ions are investigated using first-principles quantum mechanical calculations. {T}heoretical infrared absorption spectra and {C}-13, and {F}-19 nuclear magnetic resonance chemical shifts are determined. {A}mong the investigated models, only the clumped ({CO}3 (2-), {F}-) defect, with the carbonate group close to the sloping face of the tetrahedral site and the {F}- ion at the remaining apex, corresponds to previous experimental observations performed on carbonate-fluorapatite samples. {A}lthough the substitution of hydroxyl by fluoride ions is commonly observed in minerals, the clumped ({CO}3 (2-), {OH}-) defects are unlikely to occur in apatite, considering both their theoretical spectroscopic properties and relative stability. {A}nionic {F}- for {OH}- exchange between channel and {B} sites displays a preference of 20 k{J}/mol for the local charge compensation by fluoride ions at the {B}-site, pointing to a significantly different behavior of {F}- and {OH}- ions in the charge compensation mechanism. {T}his difference is ascribed to the poor {H}-bond acceptor character of available oxygen atoms surrounding the apex of the tetrahedral site. {T}he explicit calculation of the infrared absorption spectra of the defect models is also used to interpret the significant difference observed in the linewidth of the nu(2) and nu(3) {CO}3 infrared powder absorption bands of carbonated apatite samples. {I}t is shown that for a concentration of 4.4 wt% of {CO}2, long-range electrostatic effects already significantly contribute to the broadening of the nu(3) {CO}3 bands in apatite.},
  keywords = {{A}patite ; {C}arbonate substitution ; {F}irst-principles ; {DFT} ; {FTIR} ; {NMR}},
  booktitle = {},
  journal = {{P}hysics and {C}hemistry of {M}inerals},
  volume = {41},
  numero = {5},
  pages = {347--359},
  ISSN = {0342-1791},
  year = {2014},
  DOI = {10.1007/s00269-013-0654-9},
  URL = {https://www.documentation.ird.fr/hor/fdi:010061974},
}