中文摘要：

利用基于密度泛函理论的第一性原理方法对黑索金晶体的电子结构和光学性质进行了计算．结果表明：黑索金是能隙值为3．43eV的绝缘体，价带主要由C，N和O的2s与2p态构成，而导带主要由N-2p和O-2p态构成；静态介电函数ε1（0）=1．38，介电常数的虚部有5个峰值，其中最大峰值在光子能量4．59eV处，并对造成这些峰值的可能的电子跃迁做了详细分析．利用能带结构和态密度分析了黑索金的光反射系数、吸收系数及能量损失函数等光学性质，发现黑索金是对光吸收、反射及能量损失不敏感的材料．

英文摘要：

Electronic structure and optical properties of RDX are calculated by the first-principle density function theory pseudopotential method. The calculated results show that RDX is an insulator with a band gap of 3.43 eV, that the valence band of RDX is mainly composed of C-2s, C-2p, N-2s, N-2p and O-2s, O-2p, and that the conduction bands are mainly composed of N-2p and O-2p. The static dielectric function el （0） is 1.38, the imaginary part of dielectric function has five peaks and the largest peak is at the position corresponding to 4.6 eV of photon energy. The electronic direct transitions for these peaks are analyzed in detail. The absorption, reflectivity and loss function of RDX are analyzed in terms of calculated band structure and density of states. The results indicate that the RDX is not sensitive to the optical absorption nor to reflectivity nor to energy loss.