Abstract：
Over the last decade, a tremendous research interest has been directed towards two-dimensional (2D) materials, owing to their vast diversity of chemical and physical properties, as well as their promising applications. Notably, transition metal dichalcogenides (e.g., MoS2) and MXenes (transition metal carbides/nitrides) with a formula AB2, which have characteristic geometrical atomic structures such as 1T (trigonal monolayer) and 1H (hexagonal monolayer), have attracted great attentions. This heightened interest is a result of advancements in experimental technologies like exfoliation and synthesis methods. While numerous AB2 type monolayers have already been investigated experimentally, the sheer diversity in element combinations even within the AB2 compound suggests sufficient opportunities for exploring unknown stable monolayer structures through computational materials science.
In this study, we constructed a structure map for AB2 type monolayers by high-throughput calculations based on the density functional theory by using OpenMX [1,2]. We also constructed a web-based interactive database for the structure map [3]. Moreover, we propose new types of structures such as a memory structure and buckled penta-structures [4] which were found in our high-throughput calculations.
Our structure map and its database will provide more comprehensive understanding for structural trends of 2D materials and give new viewpoints and directions to search unknown 2D materials.
References:
[1] M. Fukuda, J. Zhang, Y.-T. Lee, T. Ozaki, Mater. Adv. 2, 4392 (2021).
[2] OpenMX, http://www.openmx-square.org/.
[3] Our structure map and database are available on the interactive website (www.openmx-square.org/2d-ab2/).
[4] M. Fukuda, T. Ozaki, arXiv:2305.08111 [cond-mat.mtrl-sci]