• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >High-Pressure Structural Trends of Group 15 Elements: Simple Packed Structures versus Complex Host-Guest Arrangements
【24h】

High-Pressure Structural Trends of Group 15 Elements: Simple Packed Structures versus Complex Host-Guest Arrangements

机译：第15组元素的高压结构趋势：简单包装的结构与复杂的宾客布置

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Group 15 elements P, As, Sb, and Bi all have layered structures consisting of six-membered rings under ambient conditions and attain the body-centered cubic (bcc) structure at the highest pressures applied. In the intermediate pressure region, however, phosophorus and its heavier congeners behave profoundly differently. In this region P first attains the open packed simple cubic (sc) structure for a wide range of pressures and then transforms into the rarely observed simple hexagonal (sh) structure. For the heavier congeners complex, incommensurately modulated host-guest structures emerge as intermediate pressure structures. We investigated the high-pressure behavior of P and As by ab initio density functional calculations in which pseudopotentials and a plane wave basis set were employed. The incommensurately modulated high-pressure structure of As was approximated by a super cell. Our calculations reproduced the experimentally established pressure stability ranges of the sc and sh structures for P and the host-guest structure for As very well. We found that the sc and especially the sh structure are decisively stabilized by the admixture of d states in the occupied levels of the electronic structure. This admixture releases s-s antibonding states above the Fermi level (s-d mixing). With pressure, s-d mixing increases rapidly for P, whereas it remains at a low level for As. As a consequence, the band energy contribution to the total energy determines the structural stability for P in the intermediate pressure region, giving rise to simple packed structures. On the other hand, in the intermediate pressure region of the heavier Group 15 elements, a delicate interplay between the electrostatic Madelung energy and the band energy leads to the formation of complex structures.
机译：第15组元素P，As，Sb和Bi在环境条件下均具有由六元环组成的分层结构，并在施加的最高压力下达到了以身体为中心的立方（bcc）结构。但是，在中压区域，磷及其重的同类物的行为有很大不同。在该区域中，P首先在宽范围的压力下都获得开放堆积的简单立方（sc）结构，然后转变为鲜为人知的简单六边形（sh）结构。对于较重的同类物，作为中压结构出现了不适当调节的宿主-客体结构。我们通过从头算密度函数计算研究了P和As的高压行为，其中采用了伪势和平面波基组。超级电池近似地对As进行了无比调节的高压结构。我们的计算很好地再现了实验确定的P的sc和sh结构以及As的主客体结构的压力稳定性范围。我们发现，sc结构，尤其是sh结构在电子结构的占据能级中通过d状态的混合而得到了决定性的稳定。该混合物在费米能级以上释放s-s反键态（s-d混合）。随着压力的增加，P的s-d混合迅速增加，而As的混合则保持较低水平。结果，带能对总能量的贡献决定了中压区域中P的结构稳定性，从而产生了简单的堆积结构。另一方面，在较重的15组元素的中间压力区域中，静电马德隆能量和能带能量之间的微妙相互作用导致了复杂结构的形成。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号