In this work, the structural, electronic and absorption properties of 2-methyl-2H-naphtho-[1,8-de]triazine in the pressure ranges of 0–250[Formula: see text]GPa are studied in detail (hereinafter referred to as 2-methyl crystal). Density functional theory (DFT) is used to calculate the lattice constants, bond lengths and bond angles of 2-methyl under different pressures. The results show that the crystals undergo complex transformations under compression, and the major structural transformations occur at pressures of 90[Formula: see text]GPa and 210[Formula: see text]GPa with repeated formations and disconnections. In addition, the [Formula: see text]- and [Formula: see text]-directions of the 2-methyl are stiffer than the [Formula: see text]-direction, which indicates that the compressibility of the crystal is anisotropic. From the specific analysis of the bandgaps of 2-methyl, we can know that the crystal is converted from semiconductor to metal at 90[Formula: see text]GPa. The absorption spectrum of the crystal also indicates that 2-methyl has a relatively high optical activity with the increasing pressure.

中文翻译：

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静水压缩下2-甲基-2H-萘并[1,8-去]三嗪的结构转变和电子性质

本工作详细研究了2-甲基-2H-萘并[1,8-去]三嗪在0~250[分子式：见正文]GPa压力范围内的结构、电子和吸收性质（以下简称为 2-甲基晶体）。密度泛函理论（DFT）用于计算2-甲基在不同压力下的晶格常数、键长和键角。结果表明，晶体在压缩下发生复杂的转变，主要的结构转变发生在90[公式：见正文]GPa和210[公式：见正文]GPa的压力下，重复形成和断开。另外，2-甲基的[分子式：见文字]-和[分子式：见文字]-方向比[分子式：见文字]-方向更硬，说明晶体的可压缩性是各向异性的。从具体分析2-甲基的带隙可知，晶体在90[公式：见正文]GPa时由半导体转化为金属。晶体的吸收光谱也表明随着压力的增加2-甲基具有较高的旋光性。