Role of lone-pair electron localization in temperature-induced phase transitions in mimetite

ABSTRACT: The monoclinic-to-hexagonal phase transition in mimetite Pb5(AsO4)3Cl was investigated by in situ temperature-dependent single crystal X-ray diffraction combined with ab initio molecular dynamics simulations. The crystal structure of mimetite Pb5(AsO4)3Cl, a phosphate with apatite structure-type has been investigated in situ at 123, 173, 273, 288, 353 and 393 K. A careful inspection of the diffraction pattern and subsequent structure refinements indicated that mimetite transforms from the monoclinic to the hexagonal polymorph with increasing temperature. At 123 K, a monoclinic superstructure, mimetite-2M, with cell parameters a = 20.4487 (9),  b = 7.4362 (2), c = 20.4513 (9) Å, β = 119.953 (6)°, V = 2694.5 (2) Å3 and space group P21 was observed. From 173 to 353 K, the reflections of the s

SUBMITTER: Cametti G 

PROVIDER: S-EPMC9370212 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature