Phosphorus: First principle simulation of a liquid-liquid phase transition
Phosphorus: First principle simulation of a liquid-liquid phase transition
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DOI：
10.1063/1.1895717
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发表时间：
2005-05-08
影响因子：
4.4
通讯作者：
Meijer, EJ
中科院分区：
文献类型：
--
作者：
Ghiringhelli, LM;Meijer, EJ
我们报道了磷的液-液相变的Car-Parrinello分子动力学研究。我们采用梯度修正密度泛函（B-LYP）来描述电子结构，并在恒压下进行模拟。当压力增加时，我们观察到，沿着1500 K等温线，结构转变将分子P-4液体转化为具有网络结构的原子液体。我们的计算表明，这种转变是一阶的不连续的密度增加伴随着绝缘体到金属的过渡。转变压力显著高于通过采用较不精确的局部密度泛函（LDA）获得的转变压力[Morishita，Phys.Rev.Lett. 87，105701（2001）]，这与压力的实验值相匹配。我们认为为什么LDA的结果应该被认为是偶然的。计算得到的结构因子随相变的变化趋势与实验观察到的一致。相变过程中的结构变化的分析表明，连接和打开（“蝴蝶”）的P-4分子链可能作为种子触发从分子到网络相的过渡。(c)2005年美国物理学会。
We report a Car-Parrinello molecular dynamics study of the liquid-liquid phase transition in phosphorus. We employed a gradient corrected density functional (B-LYP) to describe the electronic structure and performed simulations at constant pressure. Upon increasing pressure we observed, along the 1500 K isotherm, a structural transition converting the molecular P-4 liquid into an atomic liquid with a network structure. Our calculations suggest this transition to be first order with a discontinuous density increase accompanied by an insulator into metal transition. The transition pressure is significantly higher than obtained by employing the less accurate local density functional (LDA) [Morishita, Phys. Rev. Lett. 87, 105701 (2001)], which matches the experimental value for the pressure. We argue why the LDA result should be considered fortuitous. The change of the calculated structure factor upon the transition shows the same trend as experimentally observed. Analysis of the structural changes during the phase transition revealed that a chain of linked and opened up ("butterfly") P-4 molecules may serve as a seed triggering the transition from the molecular to the network phase. (c) 2005 American Institute of Physics.