Li2Sr4B12O23: A new alkali and alkaline-earth metal mixed borate with [B10O18]6− network and isolated [B2O5]4− unit

► Li2Sr4B12O23 is a a novel borate discovered in the M2O-M′O-B2O3 (M=alkali-metal, M′=alkaline-earth metal) system. ► Li2Sr4B12O23 crystal structure has a three-dimensional crystal structure with [B10O18]6− network and isolated [B2O5]4− unit. ► Sr1 and Sr2 are located in two different channels constructed by 3∞[B10O18] network.