English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The crystal structure and crystal chemistry of kurnakovite from Kramer Deposit (Kern County, California), ideally MgB 3 O 3 (OH) 5 ·5H 2 O, were investigated by single-crystal neutron diffraction (data collected at 293 and 20 K) and by a series of analytical techniques aimed to determine its chemical composition. The concentration of more than 50 elements was measured. The empirical formula of the sample used in this study is Mg 0.99 (Si 0.01 B 3.00 ) Σ3.01 O 3.00 (OH) 5 ·4.98H 2 O. The fraction of rare earth elements (REE) and other minor elements are, overall, insignificant. Even the content of fluorine, as a potential OH-group substituent, is insignificant (i.e., ~0.008 wt%). The neutron structure model obtained in this study, based on intensity data collected at 293 and 20 K, shows that the structure of kurnakovite contains: [BO 2 (OH)]-groups in planar-triangular coordination (with the B-ions in  sp  2  electronic configuration), [BO 2 (OH) 2 ]-groups in tetrahedral coordination (with the B-ions in  sp  3  electronic configuration), and Mg(OH) 2 (H 2 O) 4 -octahedra, connected into (neutral) Mg(H 2 O) 4 B 3 O 3 (OH) 5  units forming infinite chains running along [001]. Chains are mutually connected to give the tri-dimensional structure only via hydrogen bonding, and extra-chains “zeolitic” H 2 O molecules are also involved as “bridging molecules.” All the oxygen sites in the structure of kurnakovite are involved in hydrogen bonding, as  donors  or as  acceptors .

A multi-methodological study of kurnakovite: A potential B-rich aggregate