Calcium phosphate clusters.
The potential energy surfaces associated with [Ca3(PO4)2n clusters are analyzed in detail using ab initio calculations for n ranging from one to four. Considering separated clusters, energy criteria favor the so-called Posner's cluster Ca9(PO4)6, which is the core of the actual structural model of amorphous calcium phosphate. This is rationalized through the existence of a distinct CaO bonding pattern in this cluster. Considering aggregated clusters as a possible model for amorphous calcium phosphate, the aggregation of Ca3(PO4)2 clusters appears as an alternative to Posner's hypothesis.
Kanzaki
N
N
School of Science and Engineering Waseda University, Tokyo, Japan.
Treboux
G
G
Onuma
K
K
Tsutsumi
S
S
Ito
A
A
D001672:Biocompatible Materials / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D046911:Macromolecular Substances; D008422:Materials Testing; D008956:Models, Chemical; D013499:Surface Properties; D013816:Thermodynamics
D001672:Biocompatible Materials; D002130:Calcium Phosphates; D046911:Macromolecular Substances; C485828:alpha-tricalcium phosphate; C519480:amorphous calcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous