Abstract
Abstract The crystal structure of lewisite, ideally (Ca,Sb 3+ ,Fe 3+ ,Al,Na,Mn,□) 2 (Sb 5+ ,Ti) 2 O 6 (OH), cubic, space group Fd3m , a =10.311(7) A, V =1096.23 A 3 , Z =8, d calc. =4.73, d obs. =4.95 g/cm 3 , F (000)=1531, has been solved by single-crystal X-ray diffraction analysis and refined to R =0.015 for 218 unique reflections with ∣ F ∣>4 σ ( F ). The pyrochlore-like structure contains distorted A cubes and B octahedra. A comparison among lewisite and several other pyrochlore-like structures with B=Sb 5+ shows that increase of the unit cell parameter depends on the size of the A-cations. XRD study of lewisite did not reveal the intergrowth of two sublattices, previously anticipated in this structure. A comparison of two models with a static distribution of Sb 3+ (splitting of the A site) and a dynamic distribution (anharmonic thermal displacements of cations in the A site) led us to prefer the latter. A structural study of romeite is now necessary to establish the identity of lewisite and romeite.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
