OICC Press International Nano Letters 2228-5326 3 1 (December 2013) 2013 03 12 Lithium metasilicate and lithium disilicate nanomaterials: optical properties and density functional theory calculations 10.1186/2228-5326-3-14 EN Abdolali Alemi Department of Inorganic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, IR Shahin Khademinia Department of Inorganic Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, IR Sang Woo Joo School of Mechanical Engineering WCU Nano Research Center, Yeungnam University, Gyeongsan, 712-749, KR Mahboubeh Dolatyari Laboratory of Photonics and Nano Crystals, School of Engineering-Emerging Technologies, University of Tabriz, Tabriz, IR Akbar Bakhtiari Department of Chemistry, Payame Noor University, Tehran, 19395-4697, IR Journal Article 2013 03 12 Abstract UV–vis and photoluminescence spectra of the hydrothermally synthesized crystalline lithium metasilicate (Li 2 SiO 3 ) and lithium disilicate (Li 2 Si 2 O 5 ) nanomaterials are studied. The intensity of the bands in the emission spectra increases with increasing reaction time in both compounds. The electronic band structure along with density of states calculated by the density functional theory (DFT) method indicates that Li 2 SiO 3 and Li 2 Si 2 O 5 have an indirect energy band gap of 4.575 and 4.776 eV respectively. The optical properties, including the dielectric, absorption, reflectivity, and energy loss spectra of the compounds, are calculated by DFT method and analyzed based on the electronic structures.