Revision of the crystal structure and chemical formula of
weeksite, K2(UO2)2(Si5O13).4H2O

J 2012

Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13).4H2O

FEJFAROVA, Karla, Jakub PLÁŠIL, Hexiong YANG, Jiri CEJKA, Michal DUŠEK et. al.

Základní údaje

Originální název

Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13).4H2O

Autoři

FEJFAROVA, Karla (203 Česká republika), Jakub PLÁŠIL (203 Česká republika, garant), Hexiong YANG (840 Spojené státy), Jiri CEJKA (203 Česká republika), Michal DUŠEK (203 Česká republika), Robert T DOWNS (840 Spojené státy), Madison C BARKLEY (840 Spojené státy) a Radek ŠKODA (203 Česká republika, domácí)

Vydání

American Mineralogist, CHANTILLY, Mineralogical Society of America, 2012, 0003-004X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10302 Condensed matter physics

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Impakt faktor

Impact factor: 2.204

Kód RIV

RIV/00216224:14310/12:00064478

Organizační jednotka

Přírodovědecká fakulta

DOI

http://dx.doi.org/10.2138/am.2012.4025

UT WoS

000302204400028

Klíčová slova anglicky

Weeksite; uranyl silicate; crystal structure; X-ray diffraction; open framework

Štítky

AKR, rivok

Změněno: 11. 4. 2013 17:06, Ing. Andrea Mikešková

Anotace

V originále

The previously published structure determination of weeksite from the Anderson mine, Arizona, U.S.A., suggested that it is orthorhombic, Cmmb, with a = 14.209(2), b = 14.248(2), c = 35.869(4) Angstr., and V = 7262(2) A^3, and an ideal chemical formula (K,Ba)1-2(UO2)2(Si5O13).H2O. Using single-crystal X-ray diffraction, electron microprobe analysis, and thermal analysis, we reexamined weeksite from the same locality. Our results demonstrate that weeksite is monoclinic, with the space group C2/m and unit-cell parameters a= 14.1957(4), b = 14.2291(5), c = 9.6305(3) A, beta = 111.578(3)degrees, V = 1808.96(10) A^3, and an ideal formula K2(UO2)2(Si5O13).4H2O. The previously reported orthorhombic unit cell is shown to result from twinning of the monoclinic cell. The structure refinement yielded R1 = 2.84% for 1632 observed reflections [Iobs greater than 3sigma(I)] and 5.42% for all 2379 reflections. The total H2O content derived from the structure refinement agrees well with that from the thermal analysis. Although the general topology of our structure resembles that reported previously, all Si sites in our structure are fully occupied, in contrast to the previous structure determination, which includes four partially occupied SiO4 tetrahedra. From our structure data on weeksite, it appears evident that the orthorhombic cell of the newly discovered weeksite-type mineral coutinhoite, ThxB1-2x(UO2)2Si5O13.3H2O, needs to be reevaluated.

Návaznosti

MSM0021622412, záměr

Název: Interakce mezi chemickými látkami, prostředím a biologickými systémy a jejich důsledky na globální, regionální a lokální úrovni (INCHEMBIOL) (Akronym: INCHEMBIOL)

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, Interakce mezi chemickými látkami, prostředím a biologickými systémy a jejich důsledky na globální , regionální a lokální úrovni

Citovat

FEJFAROVA, Karla, Jakub PLÁŠIL, Hexiong YANG, Jiri CEJKA, Michal DUŠEK, Robert T DOWNS, Madison C BARKLEY a Radek ŠKODA. Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13).4H2O. American Mineralogist. CHANTILLY: Mineralogical Society of America, 2012, roč. 97, č. 4, s. 750-754. ISSN 0003-004X. Dostupné z: https://dx.doi.org/10.2138/am.2012.4025.

@article{1092697,
   author = {Fejfarova, Karla and Plášil, Jakub and Yang, Hexiong and Cejka, Jiri and Dušek, Michal and Downs, Robert T and Barkley, Madison C and Škoda, Radek},
   article_location = {CHANTILLY},
   article_number = {4},
   doi = {http://dx.doi.org/10.2138/am.2012.4025},
   keywords = {Weeksite; uranyl silicate; crystal structure; X-ray diffraction; open framework},
   language = {eng},
   issn = {0003-004X},
   journal = {American Mineralogist},
   title = {Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13).4H2O},
   volume = {97},
   year = {2012}
}

TY  - JOUR
ID  - 1092697
AU  - Fejfarova, Karla - Plášil, Jakub - Yang, Hexiong - Cejka, Jiri - Dušek, Michal - Downs, Robert T - Barkley, Madison C - Škoda, Radek
PY  - 2012
TI  - Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13).4H2O
JF  - American Mineralogist
VL  - 97
IS  - 4
SP  - 750-754
EP  - 750-754
PB  - Mineralogical Society of America
SN  - 0003004X
KW  - Weeksite
KW  - uranyl silicate
KW  - crystal structure
KW  - X-ray diffraction
KW  - open framework
N2  - The previously published structure determination of weeksite from the Anderson mine, Arizona, U.S.A., suggested that it is orthorhombic, Cmmb, with a = 14.209(2), b = 14.248(2), c = 35.869(4) Angstr., and V = 7262(2) A^3, and an ideal chemical formula (K,Ba)1-2(UO2)2(Si5O13).H2O. Using single-crystal X-ray diffraction, electron microprobe analysis, and thermal analysis, we reexamined weeksite from the same locality. Our results demonstrate that weeksite is monoclinic, with the space group C2/m and unit-cell parameters a= 14.1957(4), b = 14.2291(5), c = 9.6305(3) A, beta = 111.578(3)degrees, V = 1808.96(10) A^3, and an ideal formula K2(UO2)2(Si5O13).4H2O. The previously reported orthorhombic unit cell is shown to result from twinning of the monoclinic cell. The structure refinement yielded R1 = 2.84% for 1632 observed reflections [Iobs greater than 3sigma(I)] and 5.42% for all 2379 reflections. The total H2O content derived from the structure refinement agrees well with that from the thermal analysis. Although the general topology of our structure resembles that reported previously, all Si sites in our structure are fully occupied, in contrast to the previous structure determination, which includes four partially occupied SiO4 tetrahedra. From our structure data on weeksite, it appears evident that the orthorhombic cell of the newly discovered weeksite-type mineral coutinhoite, ThxB1-2x(UO2)2Si5O13.3H2O, needs to be reevaluated.
ER  -

FEJFAROVA, Karla, Jakub PLÁŠIL, Hexiong YANG, Jiri CEJKA, Michal DUŠEK, Robert T DOWNS, Madison C BARKLEY a Radek ŠKODA. Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13).4H2O. \textit{American Mineralogist}. CHANTILLY: Mineralogical Society of America, 2012, roč.~97, č.~4, s.~750-754. ISSN~0003-004X. Dostupné z: https://dx.doi.org/10.2138/am.2012.4025.

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