First Principles Investigation of Mineral Component of Bone: CO3 Substitutions in Hydroxyapatite

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• 作者：R. Astala and M. J. Stott
• 刊名：Chemistry of Materials
• 出版年：2005
• 出版时间：August 9, 2005
• 年：2005
• 卷：17
• 期：16
• 页码：4125 - 4133
• 全文大小：267K
• 年卷期：v.17,no.16(August 9, 2005)
• ISSN：1520-5002

文摘

First principles calculations are used to investigate carbonated hydroxyapatite, a naturally occurringmineral and also the inorganic component of animal bone. Two types of carbonate substitution arestudied: A-type in which the carbonate ion substitutes for an OH and B-type where the substitution isfor a phosphate. Both types have unbalanced charges and various forms of charge compensation aretreated. The methods, which are based on density functional theory and first principles pseudopotentials,yield equilibrium atomic arrangements, changes in lattice parameters, and total energies for differenttypes of substitution. When calculated energies of selected stable compounds are used, the formationenergies of different carbonate substitutions with accompanying charge compensation defects can becompared. The results indicate that compact complexes are energetically favored, and a B-type materialwith charge compensation by a calcium vacancy together with a hydrogen atom which bonds to aneighboring phosphate is the most stable of all those considered.