We applied single-crystal X-ray diffraction and Raman spectroscopy in a diamond anvil cell up to 36 GPa and first principles theoretical calculations to study the molecular dissociation of solid iodine at high pressure. Unlike previously reported, we find that the familiar Cmce molecular phase transforms to a Cmc21 molecular structure at 16 GPa, and then to an incommensurate dynamically disordered Fmmm(00γ)s00 structure at 20 GPa, which can be viewed as a stepwise formation of polymeric zigzag chains of three iodine atoms following by the formation of the dynamically dissociated, incommensurately modulated i-Fmmm phase, and the truly monatomic Immm phase at higher pressures.
Effects of Compression on the Local Iodine Environment in Dipotassium Zinc Tetraiodate(V) Dihydrate K2Zn(IO3)4.2H2O
Universitat de Valencia（瓦伦西亚大学）；Universitat Politècnica de València（瓦伦西亚理工大学）；Université Amar Telidji de Laghouat（拉格瓦特阿马尔泰利吉大学）；CELLS-ALBA Synchrotron Light Facility（CELLS-ALBA同步辐射光源设施）
Structural and electronic properties of $α,β$-(BEDT-TTF)$_2$I$_3$ and $κ$-(BEDT-TTF)$_2$X$_3$ (X=I,F,Br,Cl) organic charge transfer salts
（BEDT-TFF）$_2$ I $_3$电荷转移盐具有超导电性和压力诱导的准二维狄拉克锥。在密度泛函理论的框架下，采用从头计算方法研究了三种结构相$α$、$β$和$κ$的结构和电子性质. \edit{We furthermore report about the irreducible representations of the corresponding electronic band structures, symmetry of their crystal structure, and discuss the origin of band crossings. Additionally, we discuss the chemically induced strain in $κ$-(BEDT-TTF)$_2$I$_3$ achieved by replacing the Iodine layer with other Halogens: Fluorine, Bromine and Chlorine. In the case of $κ$-(BEDT-TTF)$_2$F$_3$, we identify topologically protected crossings within the band structure. These crossings are forc…
Structural Evolution during Reversible Halogen Intercalation into WTe2: Commensurate-Incommensurate WTe2I and Multistage WTe2Brx (x = 0.5, 1.0 and 1.25)
Department of Materials, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague（布拉格捷克理工大学核科学与物理工程学院材料系）
Crystal structure, stability and optoelectronic properties of the organic-inorganic wide bandgap perovskite CH3NH3BaI3: Candidate for transparent conductor applications
从理论和实验两方面研究了CH_3NH_3BaI_3杂化钙钛矿的结构稳定性、电子结构和光学性质。溶液处理的薄膜的CH 3 NH3 BaI 3表现出约3.87 eV的高带隙，这是非常符合4 eV的理论估计。此外，该薄膜的XRD图案与从CH_3 NH_3Ba_I_3的弛豫晶胞获得的模拟图案的L-峰匹配良好，其在I_4/mcm空间群中结晶，具有晶格参数a = 9.30 A，c = 13.94 A。原子投影态密度和能带结构计算揭示了导带和价带边缘分别主要由钡d轨道和碘p轨道组成。CH_3 NH_3BaI_3的带隙比CH_3 NH_3 PbI_3的带隙大，这是由于Ba{2+}的价带中d轨道的缺乏和较低的电负性。更详细的分析揭示了CH 3 NH3 BaI 3对湿度的优异化学和机械稳定性，不像其卤化铅对应物，在这种条件下会降解。CH 3 NH3 BaI 3化合物的可掺杂性（例如通过在Ba位点上掺杂La）与其在环境条件下的结构和机械稳定性相结合，表明该化合物是透明导体应用的有希望的候选者，特别是对于所有钙钛矿太阳能电池。
Unlock Anionic Behavior of Calcium Through Pressure Engineering
School of Physics and Electronic Information, Yantai University（烟台大学物理与电子信息学院）；Center for High Pressure Science and Technology Advanced Research（高压科学和技术先进研究中心）；Japan Synchrotron Radiation Research Institute（日本同步辐射研究所）
