Mbar Chemistry: Novel States of Matter at Extreme Conditions

技术概要：高压的应用显著改变了原子间的距离，从而改变了分子间相互作用、化学键合、分子构型、晶体结构和固体稳定性的性质。随着高压技术的现代进步，实现晶格的大压缩（通常高达几倍）是可行的，在这种条件下，材料可以很容易地被迫进入新的物理和化学构型。因此，高压提供了更多的机会来发现新的相，包括稳定的和亚稳定的相，并在宽范围的原子长度尺度上调整新的性质，基本上大于（通常是几个数量级）的那些实现了其他热（温度变化）和化学这项工作的目标是研究简单低密度物质中发生的新的物质状态和新的现象，Z分子就像百万巴压力下的二氧化碳和氮气。在这些条件下通常观察到的是金属和非金属扩展固体，它们可以在三维网络结构中储存大量能量。然而，低Z固体的大的内聚能产生了极其刚性的晶格和新颖的电子和光学性质。一般来说，这些分子到非分子的转变是由于电子离域而发生的，表现为高密度下电子动能的快速增加，但关于化学键合的确切性质，相稳定性和化学机制还有许多悬而未决的问题。许多问题是固态化学和凝聚态物理学的基本问题，将在本项目中得到解决。非技术摘要：本项目中概述的研究将影响基础固态化学和凝聚态材料科学，最终将在Mbars建立新的元素和固体周期顺序。该项目还将通过在华盛顿州立大学（WSU）和同步加速器设施和国家实验室提供尖端实验技术的实践研究经验，对培养研究生和本科生产生重大影响。本研究将带来的兴奋的高压材料研究的科学家和学生在斯波坎和附近地区远远超出了WSU，从而提高公众的基本材料研究的相关性，以未来和社会的赞赏。因此，该项目的好处远远超出了本提案的直接科学范围。

TECHNICAL SUMMARY: Application of high pressure significantly alters the interatomic distance and, thus, the nature of intermolecular interaction, chemical bonding, molecular configuration, crystal structure, and stability of solid. With modern advances in high-pressure technologies, it is feasible to achieve a large (often up to a several-fold) compression of lattice, at which condition material can be easily forced into a new physical and chemical configuration. The high-pressure thus offers enhanced opportunities to discover new phases, both stable and metastable ones, and to tune novel properties in a wide-range of atomistic length scale, substantially greater than (often being several orders of) those achieved by other thermal (varying temperatures) and chemical (varying composition or making alloys) means.The goal of this proposed work is to investigate new states of matter and novel phenomena occurring in simple low-Z molecules like carbon dioxide and nitrogen at Mbar pressures. Commonly observed at these conditions are metallic and nonmetallic extended solids that can store a large sum of energy in their three-dimensional network structures. Yet, a large cohesive energy of low Z solids gives rise to an extremely stiff lattice and novel electronic and optical properties. Broadly speaking, these molecular-to-nonmolecular transitions occur due to electron delocalization manifested as a rapid increase in electron kinetic energy at high density, but there are many outstanding questions regarding the exact nature of chemical bonding, phase stability, and chemical mechanisms. Many of the questions are fundamental problems in solid state chemistries and condensed matter physics, which will be addressed in this project.NON-TECHNICAL SUMMARY: The research outlined in this proposal will impact fundamental solid-state chemistries and condensed materials sciences, which will eventually establish new Periodic orders of elements and solids at Mbars. The project will also have significant impacts on training graduate and undergraduate students by providing hands-on research experiences in cutting-edge experimental technologies at Washington State Univerisity (WSU) and at synchrotron facilities and national laboratories. The present study will bring the excitement of high-pressure materials research to the scientists and students in Spokane and nearby areas well beyond the WSU and, thus, enhance public appreciation of the relevance of fundamental materials research to the future and society. Hence, the benefits of the project reach well beyond the immediate scientific scope of this proposal.