(1. 東北大學(xué) 多金屬共生礦生態(tài)化冶金教育部重點(diǎn)實(shí)驗(yàn)室，沈陽(yáng) 110819；
2. 東北大學(xué) 冶金學(xué)院，沈陽(yáng) 110819)
摘 要: 建立完整的CaO·SiO2晶體模型并模擬晶體中Ca原子缺失缺陷的形成，對(duì)鈣硅比為0.91~1.00的CaO·SiO2晶體進(jìn)行幾何優(yōu)化。運(yùn)用CASTEP計(jì)算其晶格參數(shù)、生成焓、布居值及鍵長(zhǎng)、態(tài)密度以及差分電荷密度。結(jié)果表明：鈣缺失量在0~0.09范圍內(nèi)，隨著缺失Ca原子缺失量的增多，CaO·SiO2晶體的晶格參數(shù)和體積逐漸增大，生成焓逐漸增加；O—Ca鍵的布居值減小，鍵長(zhǎng)不斷增加，在費(fèi)米能級(jí)處的態(tài)密度逐漸增加；O 2p與Si 3p軌道之間的雜化作用減弱，贗能隙逐漸變窄；O和Si原子處的局域電荷密度和得失電子數(shù)減少，CaO·SiO2晶體的穩(wěn)定性逐漸下降。合成了鈣硅比分別為1.00、0.97、0.94、0.91的CaO·SiO2晶體，其在鋁酸鈉溶液中的分解率隨Ca原子缺失數(shù)的增多而增加，穩(wěn)定性降低，與模擬結(jié)果一致。
關(guān)鍵字: CaO·SiO2；鈣缺失；晶體結(jié)構(gòu)；穩(wěn)定性；計(jì)算機(jī)模擬
（1.Key Laboratory for Ecological Metallurgy of Multimetallic Mineral, Ministry of Education, Northeastern University, Shenyang 110819, China;
2. School of Metallurgy, Northeastern University, Shenyang 110819, China）
Abstract:In order to simulate the crystal defects of CaO·SiO2 caused by Ca atom deficiency, the geometry optimization of CaO·SiO2 with C/S of 0.91-1.00 was carried out. The lattice parameters, formation enthalpy, population, bond length, state density and differential charge density were calculated by CASTEP modular. The amount of calcium deficiency ranges from 0 to 0.09 as the Ca atom deficiency increases, the lattice parameters, volume and formation enthalpy of CaO·SiO2 crystal gradually increase, the population values of O—Ca bonds decrease, the bond length increases, and the state density at Fermi level increases, respectively. Meanwhile, the hybridization between O 2p and Si 3p is weakened and the pseudoenergy gap becomes narrower. The local charge density and electron number of O and Si atoms decrease, which decreases the stability of CaO·SiO2 crystal. The CaO·SiO2 compounds were synthesized when the C/S are 1.00, 0.97, 0.94 and 0.91, respectively, and their decomposition rates in sodium aluminate solution increase with the Ca atom deficiency increasing, which is consistent with the structural stability simulation.
Key words: CaO·SiO2; calcium deficiency; crystal structure; stability; computer simulation
