The article describes the results of a comprehensive study of the extra-framework components of scapolites using quantum–chemical calculations, electronic and vibrational spectroscopy, and single-crystal X-ray diffraction and crystal structure refinement. The ab initio calculations were performed using an embedded-cluster approach of extra-framework components in various cation surroundings. As a result, through comparing the experimental and ab initio calculation results, the energies of the electronic and vibrational transitions of various extra-framework components (CO3)2−, (CO3)(Formula presented.), (Formula presented.), (Formula presented.) —as well as the role of these components in the process of the lowering of the symmetry—were determined for scapolites belonging to the marialite–meionite solid–solution series. The nature of the various colors of the scapolites has also been established. Colors from purple to blue are a result of the presence of radiation-induced pairs of defects: carbonate radical anions (CO3)(Formula presented.) and F-centers. However, polysulfide (Formula presented.) radical anions are found in some violet scapolites. © 2024 by the authors.
Язык оригиналаАнглийский
ЖурналMinerals
Том14
Номер выпуска9
DOI
СостояниеОпубликовано - 13 сен 2024

ID: 126387205