Regulation of Ionic Bond in GroupⅡB Transition Metal Iodides  

作　　者：徐真真 李建福 耿延雷 张钊斌 吕阳 张超 王庆林 王晓丽 Zhenzhen Xu;Jianfu Li;Yanlei Geng;Zhaobin Zhang;Yang Lv;Chao Zhang;Qinglin Wang;Xiaoli Wang(School of Physics and Electronic Information,Yantai University,Yantai 264005,China;Shandong Key Laboratory of Optical Communication Science and Technology,School of Physics Science&Information Technology,Liaocheng University,Liaocheng 252059,China)

机构地区：[1]School of Physics and Electronic Information,Yantai University,Yantai 264005,China [2]Shandong Key Laboratory of Optical Communication Science and Technology,School of Physics Science&Information Technology,Liaocheng University,Liaocheng 252059,China

出　　处：《Chinese Physics Letters》2023年第7期40-44,共5页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11974154,11604133,and 11874318);the Taishan Scholars Special Funding for Construction Projects;the Natural Science Foundation of Shandong Province(Grant No.ZR2022MA023)。

摘　　要：Using a swarm intelligence structure search method combining with first-principles calculations,three new structures of Zn-I and Hg-I compounds are discovered and pressure-composition phase diagrams are determined.An interesting phenomenon is found,that is,the compounds that are stable at 0 GPa in both systems will decompose into their constituent elements under certain pressure,which is contrary to the general intuition that pressure always makes materials more stability and density.A detailed analysis of the decomposition mechanism reveals the increase of formation enthalpy with the increase of pressure due to contributions from bothΔU andΔ[P V].Pressure-dependent studies of theΔV demonstrate that denser materials tend to be stabilized at higher pressures.Additionally,charge transfer calculations show that external pressure is more effective in regulating the ionic bond of Hg-I,resulting in a lower decomposition pressure for HgI_(2)than for ZnI_(2).These findings have important implications for designs and syntheses of new materials,as they challenge the conventional understanding on how pressure affects stability.

关 键 词：stability. density. TRANSITION 

分 类 号：O613.44[理学—无机化学]