{"paper":{"title":"On the Structure of Vacancy Ordered Superconducting Alkali Metal Iron Selenide","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.mtrl-sci","cond-mat.str-el"],"primary_cat":"cond-mat.supr-con","authors_text":"D. M. Wang, G.F Chen, J. B. He, J. J. Ying, M. A. Green, P-Y Hsieh, P. Zavalij, Q. Huang, Wei Bao, X. F. Wang, X. H. Chen, X. Q. Wang","submitted_at":"2011-01-25T17:43:42Z","abstract_excerpt":"With single crystal X-ray diffraction studies, we compare the structures of three sample showing optimal superconductivity, K0.774(4)Fe1.613(2)Se2, K0.738(6)Fe1.631(3)Se2 and Cs0.748(2)Fe1.626(1)Se2. All have an almost identical ordered vacancy structure with a ({\\sqrt}5 x {\\sqrt}5 x 1) super cell. The tetragonal unit cell, space group I4/m, possesses lattice parameters at 250K of a = b = 8.729(2) {\\AA} and c = 14.120(3) {\\AA}, a = b = 8.7186(12) {\\AA} and c = 14.0853(19) {\\AA} and at 295 K, a = b = 8.8617(16) {\\AA} and c = 15.304(3) {\\AA} for the three crystals, respectively. The structure co"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1101.4882","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}