Structural and Electronic Properties of Sr2CoO2Cl2

We report on a first-principles study of Sr2CoO2Cl2 which contains CoO2 square planes separated by SrCl layers.Our results reveal that its striking behavior relies on the occupation of the 3d d xz /d yz orbitals of high-spin Co. Such an electronic state avoids Jahn–Teller effects, which cause electrostatic and hybridization effects. Therefore, it is easier to distinguish the shift of orbital arrangement with the variation of the Co-Cl distance and the Co-O distance.