title: Two New Crystals in Li(m)Cs(n)B(m+n)O2(m+n) (m + n = 5, 7; m > n) Series: Noncentrosymmetric Li5Cs2B7O14 and Centrosymmetric Li4CsB5O10.
abstract: With the introduction of an alkali metal into the B-O framework, two new alkali metal borate crystals, Li5Cs2B7O14 and Li4CsB5O10, have been obtained for the first time. Both compounds obey a general formula of Li(m)Cs(n)B(m+n)O2(m+n) (m + n = 5, 7; m > n). The two crystals have different three-dimensional (3D) framework structures composed by LiOn (n = 4, 5), CsO10, BO3, and BO4 units. Li5Cs2B7O14 crystallizes into the polar and noncentrosymmetric space group Ama2, while Li4CsB5O10 belongs to the nonpolar and centrosymmetric space group P21/c. Detailed structure comparison analysis indicates that the different arrangements of the anionic groups in Li(m)Cs(7-m)B7O14 (m = 4, 5) and Li(m)Cs(5-m)B5O10 (m = 3, 4) may arise from the cation size effects, bond-valence requirements, and differences of coordination environment. In addition, in order to get better understandings of electronic structures and linear optical properties, we also carried out first-principle theoretical studies.
authors.affiliation: ‡University of Chinese Academy of Sciences, Yuquan Road, 19, Beijing 100049, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.forename: Shujuan
authors.initials: S
authors.lastname: Han
authors.affiliation: ‡University of Chinese Academy of Sciences, Yuquan Road, 19, Beijing 100049, China.
authors.forename: Binghua
authors.initials: B
authors.lastname: Lei
authors.affiliation: ‡University of Chinese Academy of Sciences, Yuquan Road, 19, Beijing 100049, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Dong
authors.forename: Hongping
authors.initials: H
authors.lastname: Wu
authors.forename: Zhongxiang
authors.initials: Z
authors.lastname: Zhou
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Yang
authors.forename: Shilie
authors.initials: S
authors.lastname: Pan