标题：Theory studies on the linear and nonlinear optical properties of MnHg(SCN)_4 crystal
作者：Peng Zhang;Chao Feng;Yuqiu Jiao;Guanggang Zhou;Lili Dong;Xinqiang Wang;Guiwu Lu
作者机构：State key laboratory of heavy oil Processing, College of Science, China University of Petroleum, Beijing 102249, China;State key
来源：Optics Communications: A Journal Devoted to the Rapid Publication of Short Contributions in the Field of Optics and Interaction of Light with Matter
关键词：Density functional theory;Ionic group theory;Second-order nonlinear optics;Electronic structure
摘要：The linear and nonlinear optical properties of MnHg(SCN)_4 (MMTC) single crystal are studied by the Density Functional Theory (DFT) method. The optimized lattice constant can be compared with the experimental value. The DFT method is used to calculate the hyperpolarizability of MMTC single crystal and the second harmonic generation coefficient is studied by the ionic group theory. The obtained second harmonic generation coefficient is d_(15)=17.14-25.91 pm/V, which is in agreement with the experimental result (19.8-28.8 pm/V). It is found that the greatest contribution for the second harmonic generation of MMTC crystal is from HgS_4 anionic group.