Sampling the structure of calcium carbonate nanoparticles with metadynamics.
Sampling the structure of calcium carbonate nanoparticles with metadynamics.
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DOI：
10.1063/1.3530288
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发表时间：
2011-01
期刊：
影响因子：
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通讯作者：
D. Quigley;C. Freeman;J. Harding;P. Rodger
中科院分区：
文献类型：
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作者：
D. Quigley;C. Freeman;J. Harding;P. Rodger
采用Metadaptics对碳酸钙纳米颗粒在水中的构型进行采样，并绘制作为结晶顺序的函数的近似自由能。这些数据被用来研究预测结构在纳米级的体积和理想的表面能的有效性。结果表明，这样的预测可以确定的结构和形态的颗粒直径为3-4 nm。在恒定体积条件下，支持nanofinition作为一种机制，用于提高无定形碳酸钙的稳定性的2 nm的颗粒上的早期结果进行比较。我们的研究结果表明，结晶方解石状结构是结晶优选的纳米粒子小至2 nm的纳米限制的情况下。
Metadynamics is employed to sample the configurations available to calcium carbonate nanoparticles in water, and to map an approximate free energy as a function of crystalline order. These data are used to investigate the validity of bulk and ideal surface energies in predicting structure at the nanoscale. Results indicate that such predictions can determine the structure and morphology of particles as small as 3-4 nm in diameter. Comparisons are made to earlier results on 2 nm particles under constant volume conditions which support nanoconfinement as a mechanism for enhancing the stability of amorphous calcium carbonate. Our results indicate that crystalline calcitelike structure is thermodynamically preferred for nanoparticles as small as 2 nm in the absence of nanoconfinement.