结构和带隙封闭在密集的气中
1Laboratory of Atomic and Solid State Physics and Cornell Center for Materials Research, Cornell University, Ithaca, New York 14853-2501, USA.
Nature
|February 25, 2000
概括
自1935年以来预测的金属仍然难以捉摸. 密度函数计算表明,在特定密度下,偶联的金属状态是可能的,但实现它可能需要超出当前近似的先进计算方法.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学是一种材料科学.
- 计算化学是一种计算化学.
背景情况:
- 自1935年以来,在极大压力下过渡到金属状态已经被理论化.
- 实验实现固体金属是具有挑战性的,研究仅达到342 GPa.
- 的质子配对绝缘体结构的强度使直接金属化变得复杂.
研究的目的:
- 通过计算来研究在密集中实现配对或分子金属状态的条件.
- 探索金属的替代途径,保持分子配对.
- 评估多电子效应对预测过渡压力的影响.
主要方法:
- 在局部密度近似 (LDA) 内的密度函数计算.
- 对带结构和带隙封闭的分析.
- 将近似的多电子校正纳入LDA.
主要成果:
- LDA计算预测了一系列密度,其中一个配对或分子金属状态在能量方面受到青.
- 过渡到这种金属状态与带隙关闭有关.
- 为许多电子效应进行校正会显著改变过渡期预测的压力.
结论:
- 在特定密度条件下,中的配对或分子金属状态在计算上是合理的.
- 准确预测金属需要超越标准的LDA,结合许多电子效应.
- 需要进一步的理论发展才能完全解决密集的相位图.
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