TY - JOUR
T1 - Hydrothermal Synthesis and Structure Solution of Na2Ca(CO3)2
T2 - "synthetic Analogue" of Mineral Nyerereite
AU - Gavryushkin, Pavel N.
AU - Thomas, Victor G.
AU - Bolotina, Nadezhda B.
AU - Bakakin, Vladimir V.
AU - Golovin, Alexander V.
AU - Seryotkin, Yurii V.
AU - Fursenko, Dmitry A.
AU - Litasov, Konstantin D.
PY - 2016/4/6
Y1 - 2016/4/6
N2 - Crystals of Na2Ca(CO3)2, the structural analogues of mineral nyerereite, were synthesized using hydrothermal technique at 1 kbar and 450°C. The crystals are transformational twins formed at the transition from the high-temperature hexagonal modification to the low-temperature orthorhombic modification. The structure was solved and refined to R = 0.059 in P21ca (No. 29) space group with a = 10.0713(5) Å, b = 8.7220(2) Å, and c = 12.2460(4) Å. The only structural analogue of the synthesized crystal is the high-temperature modification of K2Ca(CO3)2, which can be considered as a disordered analogue of Na2Ca(CO3)2. Structural analogues among borates and other classes of compounds have not been found. Based on group-subgroup analysis, we propose the structures of high- and intermediate-temperature modifications of Na2Ca(CO3)2. The relations of the determined structure with other polymorphs of Na2Ca(CO3)2 have also been considered.
AB - Crystals of Na2Ca(CO3)2, the structural analogues of mineral nyerereite, were synthesized using hydrothermal technique at 1 kbar and 450°C. The crystals are transformational twins formed at the transition from the high-temperature hexagonal modification to the low-temperature orthorhombic modification. The structure was solved and refined to R = 0.059 in P21ca (No. 29) space group with a = 10.0713(5) Å, b = 8.7220(2) Å, and c = 12.2460(4) Å. The only structural analogue of the synthesized crystal is the high-temperature modification of K2Ca(CO3)2, which can be considered as a disordered analogue of Na2Ca(CO3)2. Structural analogues among borates and other classes of compounds have not been found. Based on group-subgroup analysis, we propose the structures of high- and intermediate-temperature modifications of Na2Ca(CO3)2. The relations of the determined structure with other polymorphs of Na2Ca(CO3)2 have also been considered.
UR - http://www.scopus.com/inward/record.url?scp=84964601638&partnerID=8YFLogxK
U2 - 10.1021/acs.cgd.5b01398
DO - 10.1021/acs.cgd.5b01398
M3 - Article
AN - SCOPUS:84964601638
VL - 16
SP - 1893
EP - 1902
JO - Crystal Growth and Design
JF - Crystal Growth and Design
SN - 1528-7483
IS - 4
ER -