Rietveld refinement of langbeinite-type K(2)YHf(PO(4))(3).

Potassium yttrium hafnium tris-(orthophosphate) belongs to the langbeinite-family and is built up from [MO(6)] octa-hedra [in which the positions of the two independent M sites are mutually occupied by Y and Hf in a 0.605 (10):0.395 (10) ratio] and [PO(4)] tetra-hedra connected via vertices into a three-dimensional framework. This framework is penetrated by large closed cavities in which the two independent K atoms are located; one of the K atoms is nine-coordinated and the other is 12-coordinated by surrounding O atoms. The K, Y and Hf atoms lie on threefold rotation axes, whereas the P and O atoms are located in general positions.

Related literature

For the structure of the mineral langbeinite, see: K2Mg2(SO4)3 (Zemann & Zemann, 1957 ▶). For powder diffraction investigations and Rietveld refinements of phosphate-based langbeinites, see: K2 MZr(PO4)3, M = Y, Gd (Wulff et al., 1992 ▶); K2FeZr(PO4)3 (Orlova et al., 2003 ▶); K2 LnZr(PO4)3, Ln = Ce—Lu (Trubach et al., 2004 ▶). Hafnium-containing phosphate langbeinites are reported for K2BiHf(PO4)3 (Losilla et al., 1998 ▶) and K1.93Mn0.53Hf1.47(PO4)3 (Ogorodnyk et al., 2007a ▶). For the synthesis of zirconium- or hafnium-containing langbeinite-related phosphates from fluoride precursors using flux techniques, see: Ogorodnyk et al. (2007a ▶,b ▶). Parameters needed to calculate bond-valence sums were taken from Brown & Altermatt (1985 ▶) and Brese & O’Keeffe (1991 ▶), respectively. For ionic radii, see: Shannon (1976 ▶). For crystallographic background, see: Boultif & Louër (2004 ▶).

Experimental

Crystal data

K2YHf(PO4)3

M = 630.51

Cubic,

a = 10.30748 (9) Å

V = 1095.11 (2) Å3

Z = 4

Cu Kα radiation

T = 293 K

Specimen shape: flat sheet

15 × 15 × 1 mm

Specimen prepared at 101.3 kPa

Specimen prepared at 293 K

Particle morphology: isometric, colourless

Data collection

Shimadzu XRD-6000 diffractometer

Specimen mounting: glass container

Specimen mounted in reflection mode

Scan method: step

2θmin = 5.0, 2θmax = 105.0°

Increment in 2θ = 0.02°

Refinement

R p = 5.375

R wp = 7.075

R exp = 2.809

R B = 4.248

S = 2.51

Wavelength of incident radiation: 1.540530 Å

Profile function: Thompson–Cox–Hastings pseudo-Voigt with axial divergence asymmetry (Thompson et al., 1987 ▶)

528 reflections

48 parameters

Data collection: PCXRD (Shimadzu, 2006 ▶); cell refinement: FULLPROF (Rodriguez-Carvajal, 2006 ▶); data reduction: FULLPROF; method used to solve structure: coordinates taken from an isotypic structure; program(s) used to refine structure: FULLPROF; molecular graphics: DIAMOND (Brandenburg, 1999 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶) and enCIFer (Allen et al., 2004 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809027573/wm2244sup1.cif

Rietveld powder data: contains datablocks I. DOI: 10.1107/S1600536809027573/wm2244Isup2.rtv

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

K2HfY(PO4)3	Cu Kα radiation, λ = 1.540530 Å
Mr = 630.51	T = 293 K
Cubic, P213	Particle morphology: isometric
a = 10.30748 (9) Å	colourless
V = 1095.11 (2) Å3	flat_sheet, 15 × 15 mm
Z = 4	Specimen preparation: Prepared at 293 K and 101.3 kPa
Dx = 3.824 Mg m−3

Shimadzu XRD-6000 diffractometer	Data collection mode: reflection
Radiation source: X-ray tube, X-ray	Scan method: step
graphite	2θmin = 5.02°, 2θmax = 105.02°, 2θstep = 0.02°
Specimen mounting: glass container

Rp = 5.375	Profile function: Thompson–Cox–Hastings pseudo-Voigt Axial divergence asymmetry (Thompson et al., 1987)
Rwp = 7.075	48 parameters
Rexp = 2.809	0 restraints
RBragg = 4.248	14 constraints
R(F) = 3.14	Standard least squares refinement
χ2 = 6.300	(Δ/σ)max = 0.001
5001 data points	Background function: FullProf Background 6-coeficient polynomial function
Excluded region(s): undef

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

	x	y	z	Uiso*/Ueq	Occ. (<1)
K1	0.6984 (4)	0.6984 (4)	0.6984 (4)	0.12 (9)
K2	0.9307 (5)	0.9307 (5)	0.9307 (5)	0.07 (9)
Y1	0.14694 (11)	0.14694 (11)	0.14694 (11)	0.06 (9)	0.395 (10)
Y2	0.41559 (18)	0.41559 (18)	0.41559 (18)	0.05 (9)	0.605 (10)
Hf1	0.14694 (11)	0.14694 (11)	0.14694 (11)	0.06 (9)	0.605 (10)
Hf2	0.41559 (18)	0.41559 (18)	0.41559 (18)	0.05 (9)	0.395 (10)
P1	0.4609 (5)	0.2311 (8)	0.1292 (8)	0.06 (9)
O1	0.3207 (14)	0.2448 (13)	0.0864 (15)	0.07 (9)
O2	0.5337 (12)	0.3118 (13)	0.0155 (16)	0.07 (9)
O3	0.4970 (13)	0.0965 (13)	0.1595 (13)	0.07 (9)
O4	0.4750 (14)	0.3063 (15)	0.2526 (17)	0.07 (9)

	U11	U22	U33	U12	U13	U23
K1	0.12 (9)	0.12 (9)	0.12 (9)	−0.031 (4)	−0.031 (4)	−0.031 (4)
K2	0.07 (9)	0.07 (9)	0.07 (9)	−0.019 (3)	−0.019 (3)	−0.019 (3)
Y1	0.06 (9)	0.06 (9)	0.06 (9)	0.0018 (9)	0.0018 (9)	0.0018 (9)
Y2	0.05 (9)	0.05 (9)	0.05 (9)	0.0034 (9)	0.0034 (9)	0.0034 (9)
Hf1	0.06 (9)	0.06 (9)	0.06 (9)	0.0018 (9)	0.0018 (9)	0.0018 (9)
Hf2	0.05 (9)	0.05 (9)	0.05 (9)	0.0034 (9)	0.0034 (9)	0.0034 (9)

K1—O1i	2.981 (16)	Hf1—O1xiii	2.148 (14)
K1—O2ii	3.345 (14)	Hf1—O2xiv	2.085 (15)
K1—O4ii	3.413 (16)	Hf2—O3i	2.211 (14)
K1—O1iii	2.981 (16)	Hf2—O4	2.113 (17)
K1—O2iv	3.345 (14)	Hf2—O4xi	2.113 (17)
K1—O4iv	3.413 (16)	Hf2—O3iii	2.211 (14)
K1—O1v	2.981 (16)	Hf2—O4xiii	2.113 (17)
K1—O2vi	3.345 (14)	Hf2—O3v	2.211 (14)
K1—O4vi	3.413 (16)	Y1—O1	2.148 (14)
K2—O3ii	2.907 (14)	Y1—O2x	2.085 (15)
K2—O2vii	2.912 (14)	Y1—O2xii	2.085 (15)
K2—O4ii	3.207 (17)	Y1—O1xiii	2.148 (14)
K2—O4vii	3.336 (17)	Y1—O2xiv	2.085 (15)
K2—O3iv	2.907 (14)	Y1—O1xi	2.148 (14)
K2—O2viii	2.912 (14)	Y2—O3i	2.211 (14)
K2—O4iv	3.207 (17)	Y2—O4	2.113 (17)
K2—O4viii	3.336 (17)	Y2—O3v	2.211 (14)
K2—O3vi	2.907 (14)	Y2—O4xi	2.113 (17)
K2—O2ix	2.912 (14)	Y2—O3iii	2.211 (14)
K2—O4vi	3.207 (17)	Y2—O4xiii	2.113 (17)
K2—O4ix	3.336 (17)	P1—O1	1.518 (16)
Hf1—O1	2.148 (14)	P1—O2	1.621 (17)
Hf1—O2x	2.085 (15)	P1—O3	1.470 (16)
Hf1—O1xi	2.148 (14)	P1—O4	1.497 (19)
Hf1—O2xii	2.085 (15)
O1—Hf1—O2x	97.9 (5)	O2x—Y1—O2xii	80.1 (5)
O1—Hf1—O1xi	89.3 (5)	O1xiii—Y1—O2x	172.6 (5)
O1—Hf1—O2xii	172.6 (5)	O2x—Y1—O2xiv	80.1 (5)
O1—Hf1—O1xiii	89.3 (5)	O1xi—Y1—O2xii	97.9 (5)
O1—Hf1—O2xiv	92.5 (5)	O1xi—Y1—O1xiii	89.3 (5)
O1xi—Hf1—O2x	92.5 (5)	O1xi—Y1—O2xiv	172.6 (5)
O2x—Hf1—O2xii	80.1 (5)	O1xiii—Y1—O2xii	92.5 (5)
O1xiii—Hf1—O2x	172.6 (5)	O2xii—Y1—O2xiv	80.1 (5)
O2x—Hf1—O2xiv	80.1 (5)	O1xiii—Y1—O2xiv	97.9 (5)
O1xi—Hf1—O2xii	97.9 (5)	O3i—Y2—O4	93.1 (6)
O1xi—Hf1—O1xiii	89.3 (5)	O4—Y2—O4xi	87.8 (6)
O1xi—Hf1—O2xiv	172.6 (5)	O3iii—Y2—O4	171.5 (6)
O1xiii—Hf1—O2xii	92.5 (5)	O4—Y2—O4xiii	87.8 (6)
O2xii—Hf1—O2xiv	80.1 (5)	O3v—Y2—O4	83.9 (5)
O1xiii—Hf1—O2xiv	97.9 (5)	O3i—Y2—O4xi	83.9 (5)
O3i—Hf2—O4	93.1 (6)	O3i—Y2—O3iii	95.4 (5)
O4—Hf2—O4xi	87.8 (6)	O3i—Y2—O4xiii	171.5 (6)
O3iii—Hf2—O4	171.5 (6)	O3i—Y2—O3v	95.4 (5)
O4—Hf2—O4xiii	87.8 (6)	O3iii—Y2—O4xi	93.1 (6)
O3v—Hf2—O4	83.9 (5)	O4xi—Y2—O4xiii	87.8 (6)
O3i—Hf2—O4xi	83.9 (5)	O3v—Y2—O4xi	171.5 (6)
O3i—Hf2—O3iii	95.4 (5)	O3iii—Y2—O4xiii	83.9 (5)
O3i—Hf2—O4xiii	171.5 (6)	O3iii—Y2—O3v	95.4 (5)
O3i—Hf2—O3v	95.4 (5)	O3v—Y2—O4xiii	93.1 (6)
O3iii—Hf2—O4xi	93.1 (6)	O1—P1—O2	100.5 (9)
O4xi—Hf2—O4xiii	87.8 (6)	O1—P1—O3	113.0 (9)
O3v—Hf2—O4xi	171.5 (6)	O1—P1—O4	106.9 (9)
O3iii—Hf2—O4xiii	83.9 (5)	O2—P1—O3	121.4 (8)
O3iii—Hf2—O3v	95.4 (5)	O2—P1—O4	107.7 (9)
O3v—Hf2—O4xiii	93.1 (6)	O3—P1—O4	106.5 (9)
O1—Y1—O2x	97.9 (5)	Hf1—O1—P1	131.7 (9)
O1—Y1—O1xi	89.3 (5)	Y1—O1—P1	131.7 (9)
O1—Y1—O2xii	172.6 (5)	Hf1xv—O2—P1	160.8 (9)
O1—Y1—O1xiii	89.3 (5)	Hf2xvi—O3—P1	145.6 (9)
O1—Y1—O2xiv	92.5 (5)	Hf2—O4—P1	157.5 (10)
O1xi—Y1—O2x	92.5 (5)	Y2—O4—P1	157.5 (10)

K1—O1i	2.981 (16)
K1—O2ii	3.345 (14)
K1—O4ii	3.413 (16)
K2—O3ii	2.907 (14)
K2—O2iii	2.912 (14)
K2—O4ii	3.207 (17)
K2—O4iii	3.336 (17)
M1—O1	2.148 (14)
M1—O2iv	2.085 (15)
M2—O3i	2.211 (14)
M2—O4	2.113 (17)
P1—O1	1.518 (16)
P1—O2	1.621 (17)
P1—O3	1.470 (16)
P1—O4	1.497 (19)

O1—P1—O2	100.5 (9)
O1—P1—O3	113.0 (9)
O1—P1—O4	106.9 (9)
O2—P1—O3	121.4 (8)
O2—P1—O4	107.7 (9)
O3—P1—O4	106.5 (9)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .