Lanthanite-(Nd), Nd2(CO3)3·8H2O

Morrison, S.M.; Andrade, M.B.; Wenz, M.D.; Domanik, K.J.; Downs, R.T.

doi:10.1107/S1600536813003164

inorganic compounds

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ISSN: 2056-9890

Volume 69| Part 3| March 2013| Pages i15-i16

doi:10.1107/S1600536813003164

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Lanthanite-(Nd), Nd₂(CO₃)₃·8H₂O

Shaunna M. Morrison,^a ^* Marcelo B. Andrade,^a Michelle D. Wenz,^a Kenneth J. Domanik ^b and Robert T. Downs ^a

^aDepartment of Geosciences, University of Arizona, 1040 E. 4th Street, Tucson, Arizona 85721-0077, USA, and ^bLunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd, Tucson, AZ. 85721-0092, USA
^*Correspondence e-mail: shaunnamm@email.arizona.edu

(Received 16 January 2013; accepted 30 January 2013; online 6 February 2013)

Lanthanite-(Nd), ideally Nd₂(CO₃)₃·8H₂O [dineodymium(III) tricarbonate octahydrate], is a member of the lanthanite mineral group characterized by the general formula REE₂(CO₃)₃·8H₂O, where REE is a 10-coordinated rare earth element. Based on single-crystal X-ray diffraction of a natural sample from Mitsukoshi, Hizen-cho, Karatsu City, Saga Prefecture, Japan, this study presents the first structure determination of lanthanite-(Nd). Its structure is very similar to that of other members of the lanthanite group. It is composed of infinite sheets made up of corner- and edge-sharing of two NdO₁₀-polyhedra (both with site symmetry ..2) and two carbonate triangles (site symmetries ..2 and 1) parallel to the ab plane, and stacked perpendicular to c. These layers are linked to one another only through hydrogen bonding involving the water molecules.

Related literature

For background to the lanthanite mineral group, see: Berzelius (1825 ); Blake (1853 ); Coutinho (1955 ); Shinn & Eick (1968 ); Ansell et al. (1976 ); Dal Negro et al. (1977 ); Cesbron et al. (1979 ); Roberts et al. (1980 ); Fujimori (1981 ); Svisero & Mascarenhas (1981 ); Nagashima et al. (1986 ); Atencio et al. (1989 ); Coimbra et al. (1989 ); Graham et al. (2007 ). For information on dawsonite, see: Corazza et al. (1977 ). For details of rigid-body motion, see: Downs et al. (1992 ). For resources for bond-valence calculations, see: Brese & O'Keeffe (1991 ).

Experimental

Crystal data

Nd₂(CO₃)₃·8H₂O
M_r = 612.64
Orthorhombic, P c c n
a = 8.9391 (4) Å
b = 9.4694 (4) Å
c = 16.9374 (8) Å
V = 1433.72 (11) Å³
Z = 4
Mo Kα radiation
μ = 7.25 mm⁻¹
T = 296 K
0.20 × 0.18 × 0.02 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2005 ) T_min = 0.325, T_max = 0.869
9235 measured reflections
1570 independent reflections
1373 reflections with I > 2σ(I)
R_int = 0.018

Refinement

R[F² > 2σ(F²)] = 0.020
wR(F²) = 0.057
S = 1.12
1570 reflections
102 parameters
H-atom parameters not refined
Δρ_max = 0.81 e Å⁻³
Δρ_min = −0.59 e Å⁻³

Table 1
Hydrogen-bond geometry (Å)

D—H⋯A	D⋯A
OW1⋯O1	2.645 (4)
OW1⋯OW1ⁱ	2.772 (5)
OW1⋯OW4ⁱⁱ	2.792 (5)
OW1⋯OW3ⁱⁱⁱ	2.795 (4)
OW2⋯O1^iv	2.645 (3)
OW2⋯OW2ⁱ	2.786 (5)
OW2⋯O5	2.815 (4)
OW2⋯OW4ⁱ	2.833 (5)
OW3⋯O2^v	2.626 (5)
OW3⋯OW1^iv	2.795 (4)
OW3⋯O5	2.928 (4)
OW3⋯OW3^vi	2.994 (6)
OW4⋯OW1^vii	2.792 (5)
OW4⋯OW2ⁱ	2.833 (5)
OW4⋯OW4^viii	2.909 (9)
OW4⋯OW2ⁱ	3.231 (6)
Symmetry codes: (i) $[-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z]$ ; (ii) $[-x+{\script{1\over 2}}, y, z-{\script{1\over 2}}]$ ; (iii) $[x+{\script{1\over 2}}, -y+1, -z+{\script{1\over 2}}]$ ; (iv) $[x-{\script{1\over 2}}, -y+1, -z+{\script{1\over 2}}]$ ; (v) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ ; (vi) $[-x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z]$ ; (vii) $[-x+{\script{1\over 2}}, y, z+{\script{1\over 2}}]$ ; (viii) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2004 ); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XtalDraw (Downs & Hall-Wallace, 2003 ); software used to prepare material for publication: publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536813003164/wm2719sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813003164/wm2719Isup2.hkl

checkCIF report

Comment top

Crystals of the lanthanite group minerals exhibit a thin, platy habit and are characterized by the general formula REE₂(CO₃)₃^.8H₂O, where REE is a 10-coordinated rare earth element. The group consists of lanthanite-(La), lanthanite-(Ce) and lanthanite-(Nd). The first of these minerals was found by Berzelius (1825) during one of his excursions to Bastnäs, Västmanland, Sweden, where he studied the local minerals and formulated the fundamentals of modern chemistry. Over 150 years later, Dal Negro et al. (1977) refined the crystal structure of the Bastnäs lanthanite and reported it in the non-standard setting Pbnb of space group No. 56. The chemistry of a different sample from this locality was later determined to be dominated by Ce (Atencio et al., 1989). Of the lanthanite group minerals, the structure of lanthanite-(Ce) is the only one previously determined from a natural sample. However, Shinn & Eick (1968) synthesized lanthanite-(La) and performed a refinement in the standard setting Pccn of space group No. 56.

Lanthanite-(Nd) from Bethlehem, Pennsylvania, US, was first described by Blake (1853), although it was not possible to discriminate the Nd-dominance at that time. It was not until Atencio et al. (1989) analyzed a Bethlehem sample that it was found to be Nd-rich. Lanthanite-(Nd) has since been reported from other localities, including Curitiba, Brazil (Coutinho, 1955; Ansell et al., 1976; Cesbron et al., 1979; Roberts et al., 1980; Fujimori, 1981; Svisero & Mascarenhas, 1981); Saga Prefecture, Japan (Nagashima et al., 1986); Santa Isabel, São Paulo, Brazil (Coimbra et al., 1989); and Whitianga, Coromandel Peninsula, New Zealand (Graham et al., 2007). With the exception of those found in Whitianga, all lanthanite-(Nd) samples from these localities, including the one used in this study, exhibit a predominance of Nd with sub-equal La and a notable depletion of Ce. In reference to this phenomenon, Atencio et al. (1989) stated that lanthanite minerals comprise two distinct groups: one in which the proportions of La, Ce and Nd are similar and another in which La and Nd are similar in abundance while Ce is severely depleted or entirely absent. This trend presumably stems from differences in formational conditions, but the exact mechanism(s) remain(s) unclear.

Many of the studies referenced above reported lanthanite-(Nd) unit-cell parameters, but none reported the crystal structure. This study presents the first crystal structure refinement of lanthanite-(Nd). In the course of identifying minerals for the RRUFF project (http://rruff.info), we found an un-twinned lanthanite-(Nd) sample from Mitsukoshi, Hizen-cho, Karatsu City, Saga Prefecture, Japan and performed single-crystal X-ray diffraction.

The general structure feature of lanthanite-(Nd) is that of infinite sheets of corner- and edge-sharing NdO₁₀- and carbonate-polyhedra (Fig. 1) parallel to the ab plane, and stacked perpendicular to c. The layers are linked to one another only by hydrogen bonding between water molecules (Fig. 2). This accounts for the micaceous cleavage of the lanthanite minerals (Fig. 3) (Dal Negro et al., 1977). There are two distinct Nd-sites (Nd1 and Nd2 at Wyckoff positions 4 c and 4 d), as well as two C-sites (C1 and C2 at Wyckoff positions 4 d and 8 e). Nd1 and Nd2 share an edge (O3 and O4) in the a-direction, forming a chain. The chains are linked in the b-direction by NdO₁₀ polyhedra sharing a corner (O5) and sharing edges with the C2 carbonate group. Nd1 is bonded to two water molecules (OW1 and OW2) while Nd2 is bonded to one (OW3) that protrude from the primary sheet in the c-direction. The C1 carbonate group also projects from the sheet along c. According to bond valence calculations (Brese & O'Keeffe, 1991), without accounting for hydrogen bonding, each O-atom of the C1 carbonate group is under-bonded, with bond valence sums of 1.64 and 1.47 bond valence units for O1 and O2, respectively. The two O1 atoms are bonded only to Nd2 and C1, resulting in an underbonding that is satisfied by hydrogen bonding as an acceptor of OW1 and OW2 (Table 1). The apex O-atom, O2, is not bonded to any cation other than C1 and therefore has much larger thermal displacement parameters and a shorter bond length (1.243 (8) Å) than usually found in carbonate groups. The C1—O2 bond is close to satisfying the rigid-body criteria of equal displacement amplitudes of C1 and O2 along the C1—O2 bond direction. The bond length, corrected for rigid-body motion is 1.268 Å (Downs et al., 1992). O2 is also the acceptor of an hydrogen bond from the OW3 atom of the adjacent sheet, thus connecting the two sheets. There are not many minerals with dangling O atoms in CO₃ groups, but these features are also observed in the crystal structures of isotypic lanthanite-(La) (Shinn & Eick, 1968), lanthanite-(Ce) (Dal Negro et al., 1977) and in dawsonite, NaAlCO₃(OH)₂ (Corazza et al., 1977). The last water molecule, OW4, is not bonded to any cation, but instead is situated between the OW1 of a given polyhedral layer and OW2 of the adjacent layer, linking the two layers together through hydrogen bonds.

Related literature top

For background to the lanthanite mineral group, see: Berzelius (1825); Blake (1853); Coutinho (1955); Shinn & Eick (1968); Ansell et al. (1976); Dal Negro et al. (1977); Cesbron et al. (1979); Roberts et al. (1980); Fujimori (1981); Svisero & Mascarenhas (1981); Nagashima et al. (1986); Atencio et al. (1989); Coimbra et al. (1989); Graham et al. (2007). For information on dawsonite, see: Corazza et al. (1977). For details of rigid-body motion, see: Downs et al. (1992). For resources for bond-valance calculations, see: Brese & O'Keeffe (1991).

Experimental top

The lanthanite-(Nd) specimen used in this study was from Mitsukoshi, Hizen-cho, Karatsu City, Saga Prefecture, Japan, and is in the collection of the RRUFF project (deposition No. R060993; http://rruff.info). The experimental empirical formula, (Nd_0.95La_0.61Pr_0.17Sm_0.12Gd_0.08Y_0.04Eu_0.03)_Σ₌₂(CO₃)₃^.7.97H₂O, was based on 17 O atoms and was determined from data of a CAMECA SX100 electron microprobe at the conditions of 15 keV, 10 nA, and a beam size of 20 µm. An average of 23 analysis points yielded (wt. %): H₂O 23.50 (by difference), CO₂ 21.60, Y₂O₃ 0.70, La₂O₃ 16.32, Pr₂O₃ 4.56, Nd₂O₃ 26.06, Sm₂O₃ 3.49, Eu₂O₃ 0.87, Gd₂O₃ 2.40, Tb₂O₃ 0.12, Dy₂O₃ 0.45.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XtalDraw (Downs & Hall-Wallace, 2003); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top

	Fig. 1. Looking down on a sheet of the lanthanite-(Nd) structure. NdO₁₀ polyhedra are represented in blue and carbonate triangles are represented in green.
	Fig. 2. The crystal structure of lanthanite-(Nd) represented with displacement ellipsoids at the 99% probability level. Blue, green, red and cyan represent Nd, C, O atoms and H₂O molecules, respectively.
	Fig. 3. Photograph of the lanthanite-(Nd) specimen analyzed in this study, illustrating its platy habit.

Dineodymium(III) tricarbonate octahydrate top

Crystal data top

Nd₂(CO₃)₃·8H₂O	F(000) = 1160
M_r = 612.64	D_x = 2.838 Mg m⁻³
Orthorhombic, Pccn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ab 2ac	Cell parameters from 6318 reflections
a = 8.9391 (4) Å	θ = 2.3–27.5°
b = 9.4694 (4) Å	µ = 7.25 mm⁻¹
c = 16.9374 (8) Å	T = 296 K
V = 1433.72 (11) Å³	Platy, pink
Z = 4	0.20 × 0.18 × 0.02 mm

Data collection top

Bruker APEXII CCD area-detector diffractometer	1570 independent reflections
Radiation source: fine-focus sealed tube	1373 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.018
ϕ and ω scan	θ_max = 27.5°, θ_min = 3.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2005)	h = −11→11
T_min = 0.325, T_max = 0.869	k = −10→11
9235 measured reflections	l = −21→19

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.020	H-atom parameters not refined
wR(F²) = 0.057	w = 1/[σ²(F_o²) + (0.0225P)² + 5.4801P] where P = (F_o² + 2F_c²)/3
S = 1.12	(Δ/σ)_max = 0.001
1570 reflections	Δρ_max = 0.81 e Å⁻³
102 parameters	Δρ_min = −0.59 e Å⁻³
0 restraints

Crystal data top

Nd₂(CO₃)₃·8H₂O	V = 1433.72 (11) Å³
M_r = 612.64	Z = 4
Orthorhombic, Pccn	Mo Kα radiation
a = 8.9391 (4) Å	µ = 7.25 mm⁻¹
b = 9.4694 (4) Å	T = 296 K
c = 16.9374 (8) Å	0.20 × 0.18 × 0.02 mm

Data collection top

Bruker APEXII CCD area-detector diffractometer	1570 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2005)	1373 reflections with I > 2σ(I)
T_min = 0.325, T_max = 0.869	R_int = 0.018
9235 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.020	0 restraints
wR(F²) = 0.057	H-atom parameters not refined
S = 1.12	Δρ_max = 0.81 e Å⁻³
1570 reflections	Δρ_min = −0.59 e Å⁻³
102 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Nd1	0.2500	0.2500	0.250082 (15)	0.01450 (9)
Nd2	0.2500	0.7500	0.280450 (15)	0.01381 (9)
C1	0.2500	0.7500	0.1061 (3)	0.0211 (11)
C2	0.4597 (4)	0.4972 (3)	0.28322 (19)	0.0142 (6)
O1	0.3229 (3)	0.6575 (3)	0.14676 (14)	0.0181 (5)
O2	0.2500	0.7500	0.0327 (3)	0.069 (2)
O3	0.0234 (3)	0.3837 (3)	0.20815 (16)	0.0210 (5)
O4	0.0234 (3)	0.6160 (3)	0.23732 (16)	0.0216 (5)
O5	0.3158 (3)	0.4931 (3)	0.29412 (15)	0.0192 (5)
OW1	0.3170 (3)	0.3820 (3)	0.12154 (16)	0.0232 (5)
OW2	0.1140 (3)	0.3219 (3)	0.37844 (16)	0.0261 (6)
OW3	0.1241 (3)	0.6457 (3)	0.40530 (17)	0.0343 (7)
OW4	0.3878 (6)	0.3889 (5)	0.4972 (3)	0.0749 (15)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Nd1	0.01417 (13)	0.01111 (16)	0.01822 (16)	0.00172 (9)	0.000	0.000
Nd2	0.01354 (13)	0.01037 (16)	0.01752 (16)	−0.00126 (9)	0.000	0.000
C1	0.018 (2)	0.022 (3)	0.023 (3)	0.003 (2)	0.000	0.000
C2	0.0165 (15)	0.0119 (17)	0.0143 (14)	0.0004 (12)	−0.0013 (12)	0.0014 (12)
O1	0.0181 (11)	0.0150 (12)	0.0212 (12)	0.0022 (9)	−0.0017 (9)	−0.0018 (10)
O2	0.095 (5)	0.094 (5)	0.017 (2)	0.070 (4)	0.000	0.000
O3	0.0224 (12)	0.0121 (13)	0.0284 (13)	0.0055 (10)	−0.0016 (10)	0.0001 (10)
O4	0.0188 (11)	0.0131 (14)	0.0329 (14)	−0.0039 (10)	−0.0022 (10)	−0.0029 (10)
O5	0.0128 (11)	0.0165 (13)	0.0284 (13)	0.0006 (9)	0.0027 (10)	0.0008 (10)
OW1	0.0280 (13)	0.0159 (13)	0.0255 (13)	−0.0007 (11)	0.0012 (11)	−0.0012 (10)
OW2	0.0171 (12)	0.0357 (17)	0.0254 (13)	−0.0010 (11)	0.0007 (10)	0.0006 (12)
OW3	0.0303 (15)	0.050 (2)	0.0228 (13)	−0.0153 (14)	0.0008 (11)	−0.0011 (13)
OW4	0.089 (3)	0.077 (3)	0.059 (3)	−0.028 (3)	0.035 (2)	−0.029 (2)

Geometric parameters (Å, º) top

Nd1—O5	2.491 (2)	Nd2—O5	2.513 (2)
Nd1—O5ⁱ	2.491 (2)	Nd2—O1^iv	2.514 (2)
Nd1—O3ⁱ	2.492 (2)	Nd2—O1	2.514 (2)
Nd1—O3	2.492 (2)	Nd2—OW3^iv	2.591 (3)
Nd1—OW1ⁱ	2.581 (3)	Nd2—OW3	2.591 (3)
Nd1—OW1	2.581 (3)	Nd2—O3ⁱⁱ	2.759 (3)
Nd1—OW2	2.582 (3)	Nd2—O3^v	2.759 (3)
Nd1—OW2ⁱ	2.582 (3)	Nd2—C1	2.953 (6)
Nd1—O4ⁱⁱ	2.762 (3)	Nd2—C2^iv	3.040 (3)
Nd1—O4ⁱⁱⁱ	2.762 (3)	C1—O2	1.243 (8)
Nd1—C2	3.051 (3)	C1—O1	1.291 (4)
Nd1—C2ⁱ	3.051 (3)	C1—O1^iv	1.291 (4)
Nd2—O4	2.499 (3)	C2—O4ⁱⁱ	1.263 (4)
Nd2—O4^iv	2.499 (3)	C2—O3ⁱⁱ	1.272 (4)
Nd2—O5^iv	2.513 (2)	C2—O5	1.300 (4)

O5—Nd1—O5ⁱ	145.15 (12)	O4^iv—Nd2—O5	109.18 (8)
O5—Nd1—O3ⁱ	111.28 (8)	O5^iv—Nd2—O5	169.43 (12)
O5ⁱ—Nd1—O3ⁱ	78.92 (8)	O4—Nd2—O1^iv	72.75 (8)
O5—Nd1—O3	78.92 (8)	O4^iv—Nd2—O1^iv	76.70 (8)
O5ⁱ—Nd1—O3	111.28 (8)	O5^iv—Nd2—O1^iv	71.64 (8)
O3ⁱ—Nd1—O3	146.88 (12)	O5—Nd2—O1^iv	118.74 (8)
O5—Nd1—OW1ⁱ	139.03 (8)	O4—Nd2—O1	76.70 (8)
O5ⁱ—Nd1—OW1ⁱ	75.53 (8)	O4^iv—Nd2—O1	72.75 (8)
O3ⁱ—Nd1—OW1ⁱ	72.68 (8)	O5^iv—Nd2—O1	118.74 (8)
O3—Nd1—OW1ⁱ	79.45 (8)	O5—Nd2—O1	71.64 (8)
O5—Nd1—OW1	75.53 (8)	O1^iv—Nd2—O1	51.48 (11)
O5ⁱ—Nd1—OW1	139.03 (8)	O4—Nd2—OW3^iv	141.63 (9)
O3ⁱ—Nd1—OW1	79.45 (8)	O4^iv—Nd2—OW3^iv	72.13 (9)
O3—Nd1—OW1	72.68 (8)	O5^iv—Nd2—OW3^iv	69.98 (9)
OW1ⁱ—Nd1—OW1	64.96 (12)	O5—Nd2—OW3^iv	101.07 (10)
O5—Nd1—OW2	67.38 (8)	O1^iv—Nd2—OW3^iv	135.64 (9)
O5ⁱ—Nd1—OW2	83.13 (9)	O1—Nd2—OW3^iv	139.06 (9)
O3ⁱ—Nd1—OW2	139.15 (9)	O4—Nd2—OW3	72.13 (9)
O3—Nd1—OW2	73.95 (8)	O4^iv—Nd2—OW3	141.63 (9)
OW1ⁱ—Nd1—OW2	136.78 (8)	O5^iv—Nd2—OW3	101.07 (10)
OW1—Nd1—OW2	133.78 (8)	O5—Nd2—OW3	69.98 (9)
O5—Nd1—OW2ⁱ	83.13 (9)	O1^iv—Nd2—OW3	139.06 (9)
O5ⁱ—Nd1—OW2ⁱ	67.38 (8)	O1—Nd2—OW3	135.64 (9)
O3ⁱ—Nd1—OW2ⁱ	73.95 (8)	OW3^iv—Nd2—OW3	70.59 (13)
O3—Nd1—OW2ⁱ	139.15 (9)	O4—Nd2—O3ⁱⁱ	120.36 (9)
OW1ⁱ—Nd1—OW2ⁱ	133.78 (8)	O4^iv—Nd2—O3ⁱⁱ	62.32 (9)
OW1—Nd1—OW2ⁱ	136.78 (8)	O5^iv—Nd2—O3ⁱⁱ	130.16 (8)
OW2—Nd1—OW2ⁱ	65.29 (12)	O5—Nd2—O3ⁱⁱ	48.87 (7)
O5—Nd1—O4ⁱⁱ	48.95 (8)	O1^iv—Nd2—O3ⁱⁱ	116.91 (8)
O5ⁱ—Nd1—O4ⁱⁱ	127.62 (8)	O1—Nd2—O3ⁱⁱ	70.95 (8)
O3ⁱ—Nd1—O4ⁱⁱ	62.36 (9)	OW3^iv—Nd2—O3ⁱⁱ	74.51 (9)
O3—Nd1—O4ⁱⁱ	120.53 (9)	OW3—Nd2—O3ⁱⁱ	98.79 (9)
OW1ⁱ—Nd1—O4ⁱⁱ	119.54 (8)	O4—Nd2—O3^v	62.32 (9)
OW1—Nd1—O4ⁱⁱ	68.74 (8)	O4^iv—Nd2—O3^v	120.36 (9)
OW2—Nd1—O4ⁱⁱ	103.32 (8)	O5^iv—Nd2—O3^v	48.87 (7)
OW2ⁱ—Nd1—O4ⁱⁱ	68.87 (8)	O5—Nd2—O3^v	130.16 (8)
O5—Nd1—O4ⁱⁱⁱ	127.62 (8)	O1^iv—Nd2—O3^v	70.95 (8)
O5ⁱ—Nd1—O4ⁱⁱⁱ	48.95 (8)	O1—Nd2—O3^v	116.91 (8)
O3ⁱ—Nd1—O4ⁱⁱⁱ	120.53 (9)	OW3^iv—Nd2—O3^v	98.79 (9)
O3—Nd1—O4ⁱⁱⁱ	62.36 (9)	OW3—Nd2—O3^v	74.51 (9)
OW1ⁱ—Nd1—O4ⁱⁱⁱ	68.74 (8)	O3ⁱⁱ—Nd2—O3^v	171.97 (11)
OW1—Nd1—O4ⁱⁱⁱ	119.54 (8)	O2—C1—O1	122.2 (2)
OW2—Nd1—O4ⁱⁱⁱ	68.87 (8)	O2—C1—O1^iv	122.2 (2)
OW2ⁱ—Nd1—O4ⁱⁱⁱ	103.32 (8)	O1—C1—O1^iv	115.5 (5)
O4ⁱⁱ—Nd1—O4ⁱⁱⁱ	171.14 (11)	O4ⁱⁱ—C2—O3ⁱⁱ	125.6 (3)
O4—Nd2—O4^iv	146.01 (13)	O4ⁱⁱ—C2—O5	117.4 (3)
O4—Nd2—O5^iv	109.18 (8)	O3ⁱⁱ—C2—O5	117.0 (3)
O4^iv—Nd2—O5^iv	74.05 (8)	O4ⁱⁱ—C2—O1	113.5 (2)
O4—Nd2—O5	74.05 (8)

Symmetry codes: (i) −x+1/2, −y+1/2, z; (ii) x+1/2, −y+1, −z+1/2; (iii) −x, y−1/2, −z+1/2; (iv) −x+1/2, −y+3/2, z; (v) −x, y+1/2, −z+1/2.

Hydrogen-bond geometry (Å) top

D—H···A	D···A
OW1···O1	2.645 (4)
OW1···OW1ⁱ	2.772 (5)
OW1···OW4^vi	2.792 (5)
OW1···OW3ⁱⁱ	2.795 (4)
OW2···O1^vii	2.645 (3)
OW2···OW2ⁱ	2.786 (5)
OW2···O5	2.815 (4)
OW2···OW4ⁱ	2.833 (5)
OW3···O2^viii	2.626 (5)
OW3···OW1^vii	2.795 (4)
OW3···O5	2.928 (4)
OW3···OW3^iv	2.994 (6)
OW4···OW1^ix	2.792 (5)
OW4···OW2ⁱ	2.833 (5)
OW4···OW4^x	2.909 (9)
OW4···OW2ⁱ	3.231 (6)

Symmetry codes: (i) −x+1/2, −y+1/2, z; (ii) x+1/2, −y+1, −z+1/2; (iv) −x+1/2, −y+3/2, z; (vi) −x+1/2, y, z−1/2; (vii) x−1/2, −y+1, −z+1/2; (viii) x, −y+3/2, z+1/2; (ix) −x+1/2, y, z+1/2; (x) −x+1, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	Nd₂(CO₃)₃·8H₂O
M_r	612.64
Crystal system, space group	Orthorhombic, Pccn
Temperature (K)	296
a, b, c (Å)	8.9391 (4), 9.4694 (4), 16.9374 (8)
V (Å³)	1433.72 (11)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	7.25
Crystal size (mm)	0.20 × 0.18 × 0.02

Data collection
Diffractometer	Bruker APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2005)
T_min, T_max	0.325, 0.869
No. of measured, independent and observed [I > 2σ(I)] reflections	9235, 1570, 1373
R_int	0.018
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.020, 0.057, 1.12
No. of reflections	1570
No. of parameters	102
H-atom treatment	H-atom parameters not refined
Δρ_max, Δρ_min (e Å⁻³)	0.81, −0.59

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XtalDraw (Downs & Hall-Wallace, 2003), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D···A
OW1···O1	2.645 (4)
OW1···OW1ⁱ	2.772 (5)
OW1···OW4ⁱⁱ	2.792 (5)
OW1···OW3ⁱⁱⁱ	2.795 (4)
OW2···O1^iv	2.645 (3)
OW2···OW2ⁱ	2.786 (5)
OW2···O5	2.815 (4)
OW2···OW4ⁱ	2.833 (5)
OW3···O2^v	2.626 (5)
OW3···OW1^iv	2.795 (4)
OW3···O5	2.928 (4)
OW3···OW3^vi	2.994 (6)
OW4···OW1^vii	2.792 (5)
OW4···OW2ⁱ	2.833 (5)
OW4···OW4^viii	2.909 (9)
OW4···OW2ⁱ	3.231 (6)

Symmetry codes: (i) −x+1/2, −y+1/2, z; (ii) −x+1/2, y, z−1/2; (iii) x+1/2, −y+1, −z+1/2; (iv) x−1/2, −y+1, −z+1/2; (v) x, −y+3/2, z+1/2; (vi) −x+1/2, −y+3/2, z; (vii) −x+1/2, y, z+1/2; (viii) −x+1, −y+1, −z+1.

Acknowledgements

The authors gratefully acknowledge Marcus Origlieri for providing the lanthanite-(Nd) sample to the RRUFF Project. Funding support of this study was given by the Arizona Science Foundation, the Brazilian government (CNPq 202469/2011–5) and NASA NNX11AP82A, Mars Science Laboratory Investigations. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration.

References

Ansell, H. G., Pringle, G. J. & Roberts, A. C. (1976). Geol. Sur. Can. 76-1B, 353–355. CAS Google Scholar
Atencio, D., Bevins, R. E., Fleischer, M., Williams, C. T. & Williams, P. A. (1989). Mineral. Mag. 53, 639–642. CrossRef CAS Web of Science Google Scholar
Berzelius, J. (1825). Taschenbuch für die gesamte Mineralogie mit Hinsicht auf die neuesten Entdeckungen, 19, 193–218. Google Scholar
Blake, W. P. (1853). Am. J. Sci. 16, 228–230. Google Scholar
Brese, N. E. & O'Keeffe, M. (1991). Acta Cryst. B47, 192–197. CrossRef CAS Web of Science IUCr Journals Google Scholar
Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cesbron, F., Sichère, M. C., Vachey, H., Cassedanne, J. P. & Cassedanne, J. O. (1979). Bull. Soc. Fr. Minéral. Cristallogr. 102, 342–347. CAS Google Scholar
Coimbra, A. M., Coutinho, J. M. V., Atencio, D. & Iwanuchi, W. (1989). Can. Mineral. 27, 119–123. CAS Google Scholar
Corazza, E., Sabelli, C. & Vannucci, S. (1977). Neues Jahrb. Mineral. Monatsh. pp. 381–397. Google Scholar
Coutinho, J. M. V. (1955). Bol. Fac. Fil. Ciênc. Letr. USP, 186, 119–126. Google Scholar
Dal Negro, A., Rossi, G. & Tazzoli, V. (1977). Am. Mineral. 62, 142–146. CAS Google Scholar
Downs, R. T., Gibbs, G. V., Bartelmehs, K. L. & Boisen, M. B. (1992). Am. Mineral. 77, 751–757. CAS Google Scholar
Downs, R. T. & Hall-Wallace, M. (2003). Am. Mineral. 88, 247–250. CAS Google Scholar
Fujimori, K. (1981). An. Acad. Bras. Ciênc. 53, 147–152. CAS Google Scholar
Graham, I. T., Pogson, R. E., Colchester, D. M., Hergt, J., Martin, R. & Williams, P. A. (2007). Can. Mineral. 45, 1389–1396. Web of Science CrossRef CAS Google Scholar
Nagashima, K., Miyawaki, R., Takase, J., Nakai, I., Sakurai, K., Matsubara, S., Kato, A. & Iwano, S. (1986). Am. Mineral. 71, 1028–1033. CAS Google Scholar
Roberts, A. C., Chao, G. Y. & Cesbron, F. (1980). Geol. Sur. Can. 80–1C, 141–142. CAS Google Scholar
Sheldrick, G. M. (2005). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shinn, D. B. & Eick, H. A. (1968). Inorg. Chem. 7, 1340–1345. CrossRef CAS Web of Science Google Scholar
Svisero, D. P. & Mascarenhas, Y. (1981). Atas do 3° Simp. Reg. Geol., Núcleo S. P. 1, 295–304. Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar