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The caesium titanyl arsenate structure has been studied to determine the status of the cation sites. At room temperature, residual charge density was accumulated at a distance of approximately 0.7 Å from the Cs sites. This could be attributed to partial occupancy of additional sites related by pseudo-symmetry. The occupancies of the split Cs positions were about 0.8 for the original site and 0.2 for the additional Cs position. The additional Cs positions were displaced from the two original sites along the polar c axis at distances of 0.366 (8) and 0.26 (2) Å, respectively.
Supporting information
CTA crystals were made from spontaneous growth using a self-flux of
Cs5As3O10, with 0.6 g C T A per 1 g flux, made from analytical grade
Cs2CO3, As2O5 and TiO2 (Cheng et al., 1993). The powder
starting materials were mixed thoroughly using an agate mortar and placed in a
pure Pt crucible. This was inserted into a vertical tube furnace, which was
quickly heated to 470 K where it was kept for 12 h to allow for dehydration of
the hygroscopic powders. Then the flux was slowly heated to 1230 K where it
was maintained for 24 h as the flux melt was homogenized by stirring with a Pt
spoon. Growth was accomplished by cooling from 1085 to 1066 K by 2 K per day,
after which the flux containing crystals was cooled to room temperature at a
rate of 200 K per day. Small clear crystals were recovered by dissolution in
water; some crystals had a slightly yellow colour. Many of the smaller
crystals had needle-like morphology, which has previously been observed in
supercooled melts of CTA (Cheng et al., 1993), while some of the larger
crystals had typical KTP morphology (Bolt & Bennema, 1990). However, none of
the crystals were small enough to reduce the extinction effect on the X-ray
diffraction data efficiently. Therefore, the sample chosen for the present
crystallographic study was cut from a small clear crystal of needle-like
morphology.
Full-matrix least-squares refinements were made using the independent atom
model. The Zachariasen extinction parameter r* was refined in accordance with
the Larson implementation (Larson, 1969). The minimum extinction correction
parameter ymin was 0.85 (Model I) and 0.83 (Model II) at 297 K, and
0.88 at 183 K for the 013 reflection (the observed structure factor is Fobs
= yFkin, where Fkin is the kinematical value of the structure factor). The
refined Flack (1983) parameter of 0.05 (2) at 297 K and 0.06 (2) at 183 K shows
that the crystal is nearly single-domain. The Flack parameter refinement was
made using 2188 Friedel pairs at 297 K and 2553 Friedel pairs at 183 K. For
the 183 K data, the anisotropic thermal displacement parameters for O8 and O12
showed odd values and isotropic parameters were used in the final refinements.
For all compounds, data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT and SADABS (Sheldrick, 1996); program(s) used to refine structure: Xtal (Hall et al., 1999); molecular graphics: Xtal; software used to prepare material for publication: Xtal.
Crystal data top
CsTiOAsO4 | F(000) = 1200 |
Mr = 335.7 | Dx = 4.505 Mg m−3 |
Orthorhombic, Pna21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2c -2n | Cell parameters from 6935 reflections |
a = 13.4892 (3) Å | θ = 3.0–41.8° |
b = 6.8637 (1) Å | µ = 15.54 mm−1 |
c = 10.6908 (1) Å | T = 297 K |
V = 989.82 (3) Å3 | Rectangular, colourless |
Z = 8 | 0.03 × 0.02 × 0.02 mm |
Data collection top
Siemens SMART CCD diffractometer | 6720 independent reflections |
Radiation source: fine-focus sealed tube | 4208 reflections with F2 > 3σ(F2) |
Graphite monochromator | Rint = 0.078 |
ω scans | θmax = 41.8°, θmin = 3.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −25→25 |
Tmin = 0.65, Tmax = 0.75 | k = −12→12 |
36263 measured reflections | l = −19→19 |
Refinement top
Refinement on F | 1/σ2 |
Least-squares matrix: full | (Δ/σ)max = 0.001 |
R[F2 > 2σ(F2)] = 0.038 | Δρmax = 3.14 e Å−3 |
wR(F2) = 0.026 | Δρmin = −2.39 e Å−3 |
S = 1.89 | Extinction correction: Zachariasen (1968), Eq22 p292 "Cryst. Comp." Munksgaard 1970 |
4208 reflections | Extinction coefficient: 617 (30) |
146 parameters | Absolute structure: Flack (1983) |
0 restraints | Absolute structure parameter: 0.05 (2) |
0 constraints | |
Crystal data top
CsTiOAsO4 | V = 989.82 (3) Å3 |
Mr = 335.7 | Z = 8 |
Orthorhombic, Pna21 | Mo Kα radiation |
a = 13.4892 (3) Å | µ = 15.54 mm−1 |
b = 6.8637 (1) Å | T = 297 K |
c = 10.6908 (1) Å | 0.03 × 0.02 × 0.02 mm |
Data collection top
Siemens SMART CCD diffractometer | 6720 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 4208 reflections with F2 > 3σ(F2) |
Tmin = 0.65, Tmax = 0.75 | Rint = 0.078 |
36263 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.038 | 0 restraints |
wR(F2) = 0.026 | Δρmax = 3.14 e Å−3 |
S = 1.89 | Δρmin = −2.39 e Å−3 |
4208 reflections | Absolute structure: Flack (1983) |
146 parameters | Absolute structure parameter: 0.05 (2) |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Cs1 | 0.61340 (5) | 0.21408 (7) | 0.38048 (11) | 0.0241 (3) | |
Cs2 | 0.88947 (4) | 0.30172 (7) | 0.12288 (11) | 0.0188 (3) | |
Ti1 | 0.62766 (7) | 0.4971 (2) | 0.02562 (16) | 0.0065 (5) | |
Ti2 | 0.74831 (12) | 0.7350 (2) | 0.27700 (16) | 0.0060 (5) | |
As1 | 0.49891 (7) | 0.67401 (8) | 0.28192 (12) | 0.0052 (2) | |
As2 | 0.82237 (5) | 0.49889 (12) | 0.53624 (12) | 0.0058 (2) | |
O1 | 0.5147 (6) | 0.5256 (10) | 0.1602 (5) | 0.014 (3) | |
O2 | 0.4848 (5) | 0.5392 (10) | 0.4114 (5) | 0.012 (3) | |
O3 | 0.6023 (4) | 0.8076 (8) | 0.3072 (5) | 0.010 (3) | |
O4 | 0.3980 (5) | 0.8160 (7) | 0.2620 (5) | 0.010 (3) | |
O11 | 0.7159 (5) | 0.5588 (9) | 0.1661 (5) | 0.011 (3) | |
O12 | 0.7829 (5) | 0.9428 (8) | 0.4170 (5) | 0.009 (3) | |
O5 | 0.8893 (5) | 0.6986 (8) | 0.5730 (5) | 0.013 (3) | |
O6 | 0.8893 (5) | 0.2992 (7) | 0.4986 (5) | 0.014 (3) | |
O7 | 0.7469 (5) | 0.4524 (8) | 0.6596 (5) | 0.011 (3) | |
O8 | 0.7442 (5) | 0.5510 (9) | 0.4177 (15) | 0.013 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cs1 | 0.0162 (3) | 0.0092 (2) | 0.0468 (4) | 0.00267 (18) | −0.0058 (3) | −0.0044 (2) |
Cs2 | 0.0114 (3) | 0.0125 (2) | 0.0326 (3) | 0.00286 (18) | −0.0023 (2) | −0.0046 (2) |
Ti1 | 0.0058 (4) | 0.0080 (4) | 0.0058 (5) | 0.0009 (6) | 0.0002 (4) | −0.0005 (5) |
Ti2 | 0.0056 (4) | 0.0067 (4) | 0.0056 (5) | −0.0012 (4) | −0.0001 (5) | 0.0007 (5) |
As1 | 0.0047 (2) | 0.0057 (2) | 0.0054 (3) | −0.0002 (3) | 0.0009 (3) | −0.0003 (2) |
As2 | 0.0067 (2) | 0.0054 (2) | 0.0053 (3) | 0.0001 (3) | −0.0000 (3) | 0.0005 (2) |
O1 | 0.015 (4) | 0.013 (3) | 0.014 (3) | −0.005 (2) | 0.005 (2) | −0.006 (2) |
O2 | 0.007 (3) | 0.017 (3) | 0.013 (3) | 0.005 (2) | 0.002 (2) | 0.0060 (19) |
O3 | 0.006 (3) | 0.014 (2) | 0.010 (3) | −0.002 (2) | −0.000 (2) | −0.002 (2) |
O4 | 0.007 (3) | 0.006 (2) | 0.019 (3) | 0.0009 (19) | −0.003 (2) | 0.0003 (19) |
O11 | 0.012 (3) | 0.011 (2) | 0.009 (3) | 0.001 (2) | −0.001 (2) | −0.0016 (18) |
O12 | 0.006 (3) | 0.011 (2) | 0.010 (3) | −0.001 (2) | −0.0012 (18) | −0.0032 (18) |
O5 | 0.016 (3) | 0.007 (2) | 0.015 (3) | −0.003 (2) | −0.006 (2) | 0.0011 (18) |
O6 | 0.011 (3) | 0.006 (2) | 0.024 (3) | 0.001 (2) | 0.006 (2) | 0.001 (2) |
O7 | 0.009 (3) | 0.011 (3) | 0.012 (3) | 0.003 (2) | −0.001 (2) | 0.0021 (18) |
O8 | 0.019 (4) | 0.013 (3) | 0.009 (3) | −0.008 (3) | −0.007 (2) | 0.0050 (18) |
Geometric parameters (Å, º) top
Cs1—Cs2 | 3.8378 (12) | Ti1—O5 | 2.123 (5) |
Cs1—O1 | 3.448 (6) | Ti1—O2 | 1.963 (6) |
Cs1—O2 | 2.846 (7) | Ti1—O6 | 2.106 (5) |
Cs1—O3 | 2.902 (5) | Ti1—O11 | 1.962 (6) |
Cs1—O12 | 2.974 (6) | Ti1—O12 | 1.716 (6) |
Cs1—O5 | 3.289 (5) | Ti2—O3 | 2.057 (6) |
Cs1—O6 | 3.278 (6) | Ti2—O12 | 2.119 (6) |
Cs1—O8 | 2.936 (7) | Ti2—O8 | 1.964 (13) |
Cs1—Cs2 | 4.0890 (13) | Ti2—O4i | 2.055 (6) |
Cs2—O3 | 3.377 (5) | Ti2—O11 | 1.749 (6) |
Cs2—O4 | 3.018 (5) | Ti2—O7 | 1.951 (6) |
Cs2—O11 | 2.968 (7) | As1—O1 | 1.666 (6) |
Cs2—O12 | 3.345 (6) | As1—O2 | 1.676 (6) |
Cs2—O7 | 3.048 (6) | As1—O3 | 1.691 (6) |
Cs2—O2 | 3.351 (6) | As1—O4 | 1.688 (6) |
Cs2—O8 | 3.321 (12) | As2—O5 | 1.687 (6) |
Cs2—O1 | 2.839 (7) | As2—O6 | 1.690 (6) |
Cs2—O5 | 3.032 (7) | As2—O8 | 1.687 (13) |
Ti1—O1 | 2.105 (7) | As2—O7 | 1.696 (6) |
| | | |
O1—Cs1—O2 | 50.05 (15) | O3—Ti2—O4i | 173.7 (2) |
O1—Cs1—O3 | 113.07 (15) | O3—Ti2—O11 | 92.0 (3) |
O1—Cs1—O12 | 140.77 (16) | O3—Ti2—O7 | 87.0 (2) |
O1—Cs1—O5 | 48.19 (14) | O12—Ti2—O8 | 84.2 (4) |
O1—Cs1—O6 | 85.66 (16) | O12—Ti2—O4i | 87.3 (2) |
O1—Cs1—O8 | 80.6 (3) | O12—Ti2—O11 | 177.4 (3) |
O2—Cs1—O3 | 138.93 (18) | O12—Ti2—O7 | 86.1 (2) |
O2—Cs1—O12 | 160.77 (17) | O8—Ti2—O4i | 88.7 (3) |
O2—Cs1—O5 | 97.76 (15) | O8—Ti2—O11 | 93.9 (4) |
O2—Cs1—O6 | 54.19 (16) | O8—Ti2—O7 | 170.1 (4) |
O2—Cs1—O8 | 74.5 (2) | O4i—Ti2—O11 | 94.3 (3) |
O3—Cs1—O12 | 58.21 (16) | O4i—Ti2—O7 | 92.7 (2) |
O3—Cs1—O5 | 72.45 (14) | O11—Ti2—O7 | 95.8 (3) |
O3—Cs1—O6 | 91.69 (14) | O1—As1—O2 | 108.8 (3) |
O3—Cs1—O8 | 145.6 (2) | O1—As1—O3 | 110.6 (3) |
O12—Cs1—O5 | 96.84 (15) | O1—As1—O4 | 111.0 (3) |
O12—Cs1—O6 | 129.86 (15) | O2—As1—O3 | 105.1 (3) |
O12—Cs1—O8 | 90.77 (18) | O2—As1—O4 | 109.4 (3) |
O5—Cs1—O6 | 111.98 (16) | O3—As1—O4 | 111.9 (3) |
O5—Cs1—O8 | 99.6 (3) | O5—As2—O6 | 115.4 (3) |
O6—Cs1—O8 | 121.6 (2) | O5—As2—O8 | 109.7 (3) |
O3—Cs2—O4 | 118.74 (13) | O5—As2—O7 | 107.0 (3) |
O3—Cs2—O11 | 100.04 (14) | O6—As2—O8 | 109.1 (4) |
O3—Cs2—O12 | 50.33 (14) | O6—As2—O7 | 110.7 (3) |
O3—Cs2—O7 | 99.08 (13) | O8—As2—O7 | 104.4 (4) |
O3—Cs2—O2 | 46.82 (14) | Cs1—O1—Ti1 | 97.4 (2) |
O3—Cs2—O8 | 50.5 (2) | Cs1—O1—As1 | 84.0 (2) |
O3—Cs2—O1 | 97.48 (14) | Cs1—O1—Cs2 | 80.51 (15) |
O3—Cs2—O5 | 77.98 (14) | Ti1—O1—As1 | 133.1 (4) |
O4—Cs2—O11 | 55.70 (17) | Ti1—O1—Cs2 | 105.1 (2) |
O4—Cs2—O12 | 95.69 (15) | As1—O1—Cs2 | 121.2 (3) |
O4—Cs2—O7 | 130.06 (16) | Cs1—O2—As1 | 105.5 (3) |
O4—Cs2—O2 | 141.31 (16) | Cs1—O2—Cs2 | 101.1 (2) |
O4—Cs2—O8 | 142.81 (16) | Cs1—O2—Ti1 | 116.4 (3) |
O4—Cs2—O1 | 126.59 (17) | As1—O2—Cs2 | 101.7 (3) |
O4—Cs2—O5 | 92.86 (16) | As1—O2—Ti1 | 132.2 (4) |
O11—Cs2—O12 | 51.83 (14) | Cs2—O2—Ti1 | 92.3 (2) |
O11—Cs2—O7 | 88.37 (17) | Cs1—O3—Cs2 | 74.93 (12) |
O11—Cs2—O2 | 145.46 (15) | Cs1—O3—Ti2 | 103.1 (2) |
O11—Cs2—O8 | 88.99 (17) | Cs1—O3—As1 | 127.4 (3) |
O11—Cs2—O1 | 156.64 (17) | Cs2—O3—Ti2 | 97.0 (2) |
O11—Cs2—O5 | 143.54 (16) | Cs2—O3—As1 | 100.4 (2) |
O12—Cs2—O7 | 83.85 (15) | Ti2—O3—As1 | 129.3 (3) |
O12—Cs2—O2 | 93.63 (14) | Cs2—O4—As1 | 126.5 (3) |
O12—Cs2—O8 | 48.52 (16) | Cs2—O4—Ti2 | 98.6 (2) |
O12—Cs2—O1 | 137.31 (16) | As1—O4—Ti2 | 133.2 (3) |
O12—Cs2—O5 | 124.65 (15) | Cs2—O11—Ti1 | 103.4 (2) |
O7—Cs2—O2 | 88.24 (16) | Cs2—O11—Ti2 | 108.6 (3) |
O7—Cs2—O8 | 49.4 (2) | Ti1—O11—Ti2 | 145.1 (4) |
O7—Cs2—O1 | 73.65 (19) | Cs1—O12—Cs2 | 74.54 (14) |
O7—Cs2—O5 | 128.05 (15) | Cs1—O12—Ti2 | 99.2 (2) |
O2—Cs2—O8 | 63.3 (2) | Cs1—O12—Ti1 | 119.6 (3) |
O2—Cs2—O1 | 50.82 (15) | Cs2—O12—Ti2 | 96.7 (2) |
O2—Cs2—O5 | 51.90 (15) | Cs2—O12—Ti1 | 96.1 (2) |
O8—Cs2—O1 | 90.34 (17) | Ti2—O12—Ti1 | 141.1 (4) |
O8—Cs2—O5 | 114.7 (2) | Cs1—O5—Ti1 | 101.9 (2) |
O1—Cs2—O5 | 55.84 (18) | Cs1—O5—As2 | 104.7 (2) |
O1—Ti1—O5 | 81.3 (2) | Cs1—O5—Cs2 | 80.50 (14) |
O1—Ti1—O2 | 82.9 (3) | Ti1—O5—As2 | 132.1 (3) |
O1—Ti1—O6 | 85.6 (3) | Ti1—O5—Cs2 | 98.5 (2) |
O1—Ti1—O11 | 84.0 (3) | As2—O5—Cs2 | 124.5 (3) |
O1—Ti1—O12 | 172.8 (3) | Cs1—O6—As2 | 127.4 (3) |
O5—Ti1—O2 | 86.7 (3) | Cs1—O6—Ti1 | 97.2 (2) |
O5—Ti1—O6 | 166.2 (3) | As2—O6—Ti1 | 135.1 (4) |
O5—Ti1—O11 | 95.2 (2) | Cs2—O7—Ti2 | 134.8 (3) |
O5—Ti1—O12 | 91.6 (3) | Cs2—O7—As2 | 96.6 (2) |
O2—Ti1—O6 | 87.5 (3) | Ti2—O7—As2 | 128.6 (4) |
O2—Ti1—O11 | 166.4 (3) | Cs1—O8—Cs2 | 99.9 (3) |
O2—Ti1—O12 | 95.5 (3) | Cs1—O8—Ti2 | 114.8 (6) |
O6—Ti1—O11 | 87.6 (2) | Cs1—O8—As2 | 108.1 (4) |
O6—Ti1—O12 | 101.4 (3) | Cs2—O8—Ti2 | 100.8 (2) |
O11—Ti1—O12 | 97.9 (3) | Cs2—O8—As2 | 87.3 (6) |
O3—Ti2—O12 | 86.4 (2) | Ti2—O8—As2 | 134.0 (4) |
O3—Ti2—O8 | 90.5 (3) | | |
Symmetry code: (i) x+1/2, −y+1/2, z. |
Crystal data top
CsTiOAsO4 | F(000) = 1200 |
Mr = 335.7 | Dx = 4.505 Mg m−3 |
Orthorhombic, Pna21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2c -2n | Cell parameters from 6935 reflections |
a = 13.4892 (3) Å | θ = 3.0–41.8° |
b = 6.8637 (1) Å | µ = 15.54 mm−1 |
c = 10.6908 (1) Å | T = 297 K |
V = 989.82 (3) Å3 | Rectangular, colourless |
Z = 8 | 0.03 × 0.02 × 0.02 mm |
Data collection top
Siemens SMART CCD diffractometer | 6720 independent reflections |
Radiation source: fine-focus sealed tube | 4208 reflections with F2 > 3σ(F2) |
Graphite monochromator | Rint = 0.078 |
ω scans | θmax = 41.8°, θmin = 3.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −25→25 |
Tmin = 0.65, Tmax = 0.75 | k = −12→12 |
36263 measured reflections | l = −19→19 |
Refinement top
Refinement on F | 1/σ2 |
Least-squares matrix: full | (Δ/σ)max = 0.001 |
R[F2 > 2σ(F2)] = 0.034 | Δρmax = 1.41 e Å−3 |
wR(F2) = 0.023 | Δρmin = −1.26 e Å−3 |
S = 1.73 | Extinction correction: Zachariasen (1968), Eq22 p292 "Cryst. Comp." Munksgaard 1970 |
4208 reflections | Extinction coefficient: 712 (29) |
164 parameters | Absolute structure: Flack (1983) |
0 restraints | Absolute structure parameter: 0.05 (2) |
0 constraints | |
Crystal data top
CsTiOAsO4 | V = 989.82 (3) Å3 |
Mr = 335.7 | Z = 8 |
Orthorhombic, Pna21 | Mo Kα radiation |
a = 13.4892 (3) Å | µ = 15.54 mm−1 |
b = 6.8637 (1) Å | T = 297 K |
c = 10.6908 (1) Å | 0.03 × 0.02 × 0.02 mm |
Data collection top
Siemens SMART CCD diffractometer | 6720 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 4208 reflections with F2 > 3σ(F2) |
Tmin = 0.65, Tmax = 0.75 | Rint = 0.078 |
36263 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.023 | Δρmax = 1.41 e Å−3 |
S = 1.73 | Δρmin = −1.26 e Å−3 |
4208 reflections | Absolute structure: Flack (1983) |
164 parameters | Absolute structure parameter: 0.05 (2) |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Cs1 | 0.6139 (3) | 0.2148 (5) | 0.3757 (2) | 0.0179 (6) | .800 |
Cs2 | 0.8892 (3) | 0.3002 (5) | 0.1198 (5) | 0.0145 (7) | .79600 |
Ti1 | 0.62763 (6) | 0.4970 (2) | 0.02607 (17) | 0.0068 (4) | |
Ti2 | 0.74834 (11) | 0.73465 (17) | 0.27740 (17) | 0.0059 (4) | |
As1 | 0.49890 (6) | 0.67407 (7) | 0.28238 (14) | 0.0055 (2) | |
As2 | 0.82235 (4) | 0.49891 (11) | 0.53681 (13) | 0.0061 (2) | |
O1 | 0.5145 (5) | 0.5257 (9) | 0.1611 (4) | 0.014 (3) | |
O2 | 0.4848 (5) | 0.5387 (9) | 0.4121 (4) | 0.012 (3) | |
O3 | 0.6022 (4) | 0.8074 (7) | 0.3077 (4) | 0.010 (2) | |
O4 | 0.3978 (4) | 0.8158 (6) | 0.2616 (4) | 0.011 (2) | |
O11 | 0.7161 (5) | 0.5583 (8) | 0.1669 (5) | 0.012 (3) | |
O12 | 0.7829 (4) | 0.9422 (7) | 0.4176 (4) | 0.009 (2) | |
O5 | 0.8887 (4) | 0.6994 (7) | 0.5735 (4) | 0.011 (2) | |
O6 | 0.8897 (4) | 0.3001 (7) | 0.4998 (5) | 0.012 (2) | |
O7 | 0.7470 (4) | 0.4527 (7) | 0.6603 (4) | 0.011 (3) | |
O8 | 0.7440 (5) | 0.5510 (8) | 0.4180 (4) | 0.014 (3) | |
Cs3 | 0.6109 (11) | 0.2099 (18) | 0.4096 (7) | 0.017 (2) | .200 |
Cs4 | 0.8901 (12) | 0.306 (2) | 0.1437 (17) | 0.025 (4) | .204 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cs1 | 0.0163 (5) | 0.0096 (3) | 0.0278 (10) | 0.0028 (3) | −0.0039 (8) | −0.0027 (7) |
Cs2 | 0.0098 (5) | 0.0118 (6) | 0.0220 (10) | 0.0021 (4) | −0.0019 (5) | −0.0046 (6) |
Ti1 | 0.0060 (4) | 0.0082 (4) | 0.0063 (5) | 0.0009 (5) | 0.0005 (4) | −0.0009 (4) |
Ti2 | 0.0058 (4) | 0.0065 (4) | 0.0056 (5) | −0.0011 (3) | −0.0003 (4) | 0.0007 (4) |
As1 | 0.0049 (2) | 0.00591 (19) | 0.0059 (2) | −0.0001 (3) | 0.0010 (2) | −0.0002 (2) |
As2 | 0.0070 (2) | 0.00561 (19) | 0.0057 (2) | 0.0002 (3) | −0.0001 (3) | 0.0005 (2) |
O1 | 0.014 (3) | 0.014 (2) | 0.014 (3) | −0.005 (2) | 0.0053 (18) | −0.0059 (17) |
O2 | 0.008 (3) | 0.016 (2) | 0.013 (3) | 0.005 (2) | 0.0022 (17) | 0.0059 (17) |
O3 | 0.005 (2) | 0.013 (2) | 0.011 (2) | −0.0012 (18) | 0.0002 (17) | −0.0035 (17) |
O4 | 0.009 (2) | 0.0077 (18) | 0.015 (3) | 0.0013 (17) | −0.0017 (18) | 0.0003 (17) |
O11 | 0.012 (3) | 0.012 (2) | 0.010 (2) | 0.0022 (18) | −0.0002 (19) | −0.0020 (17) |
O12 | 0.007 (3) | 0.010 (2) | 0.009 (2) | −0.0016 (17) | −0.0025 (16) | −0.0017 (15) |
O5 | 0.015 (2) | 0.0069 (18) | 0.011 (2) | −0.003 (2) | −0.003 (2) | 0.0013 (16) |
O6 | 0.012 (2) | 0.0080 (18) | 0.016 (3) | 0.001 (2) | 0.006 (2) | −0.0002 (17) |
O7 | 0.011 (3) | 0.012 (2) | 0.009 (3) | 0.003 (2) | −0.0011 (18) | 0.0017 (16) |
O8 | 0.018 (3) | 0.013 (2) | 0.010 (3) | −0.008 (2) | −0.005 (2) | 0.0056 (16) |
Cs3 | 0.0152 (16) | 0.0084 (14) | 0.028 (4) | 0.0015 (13) | −0.001 (3) | −0.004 (3) |
Cs4 | 0.021 (2) | 0.0145 (19) | 0.041 (7) | 0.0071 (16) | −0.010 (3) | −0.019 (3) |
Geometric parameters (Å, º) top
Cs1—O1 | 3.408 (6) | Cs4—O7 | 3.057 (17) |
Cs1—O2 | 2.851 (7) | Cs4—O2 | 3.515 (17) |
Cs1—O3 | 2.893 (6) | Cs4—O8 | 3.49 (2) |
Cs1—O11 | 3.528 (6) | Cs4—O3 | 3.594 (17) |
Cs1—O12 | 2.983 (7) | Cs4—O12 | 3.486 (17) |
Cs1—O5 | 3.233 (5) | Cs4—O1i | 2.837 (17) |
Cs1—O6 | 3.303 (7) | Cs4—O5 | 3.076 (17) |
Cs1—O7 | 3.473 (6) | Ti1—O1 | 2.109 (6) |
Cs1—O8 | 2.934 (7) | Ti1—O11 | 1.967 (6) |
Cs1—Cs3 | 0.366 (8) | Ti1—O5 | 2.116 (5) |
Cs2—O4 | 3.043 (6) | Ti1—O2 | 1.960 (6) |
Cs2—O11 | 2.974 (7) | Ti1—O6 | 2.112 (5) |
Cs2—O7 | 3.041 (6) | Ti1—O12 | 1.716 (5) |
Cs2—O2 | 3.323 (7) | Ti2—O4 | 2.052 (6) |
Cs2—O8 | 3.287 (7) | Ti2—O11 | 1.747 (5) |
Cs2—O3 | 3.339 (7) | Ti2—O8 | 1.962 (18) |
Cs2—O12 | 3.318 (7) | Ti2—O3 | 2.059 (5) |
Cs2—O1i | 2.838 (7) | Ti2—O12 | 2.120 (5) |
Cs2—O5 | 3.036 (7) | Ti2—O7 | 1.952 (5) |
Cs2—Cs4 | 0.260 (18) | As1—O1 | 1.663 (5) |
Cs3—O2 | 2.826 (15) | As1—O2 | 1.681 (5) |
Cs3—O3 | 2.972 (13) | As1—O3 | 1.689 (5) |
Cs3—O12 | 2.961 (15) | As1—O4 | 1.690 (5) |
Cs3—O5 | 3.594 (9) | As2—O5 | 1.688 (5) |
Cs3—O6 | 3.136 (15) | As2—O7 | 1.696 (5) |
Cs3—O8 | 2.952 (15) | As2—O6 | 1.686 (5) |
Cs4—O4 | 2.885 (16) | As2—O8 | 1.691 (5) |
Cs4—O11 | 2.926 (17) | | |
| | | |
O1—Cs1—O2 | 50.47 (14) | Cs3—O3—Cs2 | 69.3 (2) |
O1—Cs1—O3 | 114.47 (16) | Cs3—O3—Cs4 | 68.5 (3) |
O1—Cs1—O11 | 46.30 (15) | As1—O3—Cs2 | 100.4 (2) |
O1—Cs1—O12 | 142.58 (17) | As1—O3—Cs4 | 100.5 (3) |
O1—Cs1—O5 | 48.94 (13) | Cs2—O3—Cs4 | 0.8 (2) |
O1—Cs1—O6 | 85.98 (16) | Cs2—O4—Cs4 | 4.0 (4) |
O1—Cs1—O7 | 95.17 (14) | Cs2—O4—Ti2 | 98.6 (2) |
O1—Cs1—O8 | 81.16 (16) | Cs2—O4—As1 | 126.5 (3) |
O2—Cs1—O3 | 139.0 (2) | Cs4—O4—Ti2 | 98.8 (4) |
O2—Cs1—O11 | 78.70 (16) | Cs4—O4—As1 | 127.1 (4) |
O2—Cs1—O12 | 159.31 (18) | Ti2—O4—As1 | 133.2 (3) |
O2—Cs1—O5 | 98.92 (16) | Cs1—O11—Cs2 | 90.92 (17) |
O2—Cs1—O6 | 53.85 (16) | Cs1—O11—Ti1 | 96.0 (2) |
O2—Cs1—O7 | 145.54 (16) | Cs1—O11—Cs4 | 88.4 (4) |
O2—Cs1—O8 | 74.40 (19) | Cs1—O11—Ti2 | 97.6 (2) |
O3—Cs1—O11 | 120.52 (16) | Cs2—O11—Ti1 | 102.7 (2) |
O3—Cs1—O12 | 58.22 (16) | Cs2—O11—Cs4 | 5.0 (4) |
O3—Cs1—O5 | 73.53 (14) | Cs2—O11—Ti2 | 109.4 (3) |
O3—Cs1—O6 | 91.22 (16) | Ti1—O11—Cs4 | 107.2 (4) |
O3—Cs1—O7 | 50.37 (14) | Ti1—O11—Ti2 | 144.8 (3) |
O3—Cs1—O8 | 146.2 (2) | Cs4—O11—Ti2 | 105.5 (4) |
O11—Cs1—O12 | 102.44 (17) | Cs1—O12—Ti2 | 98.5 (2) |
O11—Cs1—O5 | 52.66 (13) | Cs1—O12—Cs3 | 7.05 (15) |
O11—Cs1—O6 | 129.24 (16) | Cs1—O12—Cs2 | 75.37 (15) |
O11—Cs1—O7 | 73.45 (14) | Cs1—O12—Ti1 | 120.1 (2) |
O11—Cs1—O8 | 48.55 (13) | Cs1—O12—Cs4 | 76.1 (3) |
O12—Cs1—O5 | 97.92 (15) | Ti2—O12—Cs3 | 103.0 (3) |
O12—Cs1—O6 | 128.31 (16) | Ti2—O12—Cs2 | 96.3 (2) |
O12—Cs1—O7 | 50.33 (13) | Ti2—O12—Ti1 | 141.3 (3) |
O12—Cs1—O8 | 90.75 (18) | Ti2—O12—Cs4 | 99.4 (3) |
O5—Cs1—O6 | 112.97 (17) | Cs3—O12—Cs2 | 69.7 (2) |
O5—Cs1—O7 | 47.64 (13) | Cs3—O12—Ti1 | 115.8 (3) |
O5—Cs1—O8 | 100.72 (16) | Cs3—O12—Cs4 | 70.2 (4) |
O6—Cs1—O7 | 138.15 (16) | Cs2—O12—Ti1 | 96.7 (2) |
O6—Cs1—O8 | 120.66 (17) | Cs2—O12—Cs4 | 3.3 (3) |
O7—Cs1—O8 | 100.73 (17) | Ti1—O12—Cs4 | 93.5 (3) |
O4—Cs2—O11 | 55.21 (17) | Cs1—O5—Ti1 | 101.96 (18) |
O4—Cs2—O7 | 129.1 (2) | Cs1—O5—As2 | 104.7 (2) |
O4—Cs2—O2 | 141.4 (2) | Cs1—O5—Cs3 | 1.0 (2) |
O4—Cs2—O8 | 143.0 (2) | Cs1—O5—Cs2 | 81.26 (17) |
O4—Cs2—O3 | 118.93 (17) | Cs1—O5—Cs4 | 76.5 (4) |
O4—Cs2—O12 | 95.55 (16) | Ti1—O5—As2 | 132.5 (3) |
O4—Cs2—O1i | 125.6 (2) | Ti1—O5—Cs3 | 102.7 (3) |
O4—Cs2—O5 | 92.46 (17) | Ti1—O5—Cs2 | 98.1 (2) |
O11—Cs2—O7 | 88.21 (18) | Ti1—O5—Cs4 | 99.9 (3) |
O11—Cs2—O2 | 146.8 (2) | As2—O5—Cs3 | 104.5 (3) |
O11—Cs2—O8 | 89.55 (18) | As2—O5—Cs2 | 124.2 (2) |
O11—Cs2—O3 | 100.82 (17) | As2—O5—Cs4 | 124.1 (4) |
O11—Cs2—O12 | 52.13 (14) | Cs3—O5—Cs2 | 80.6 (3) |
O11—Cs2—O1i | 155.6 (2) | Cs3—O5—Cs4 | 75.8 (4) |
O11—Cs2—O5 | 143.29 (19) | Cs2—O5—Cs4 | 4.8 (3) |
O7—Cs2—O2 | 88.89 (17) | Cs1—O6—Cs3 | 5.80 (16) |
O7—Cs2—O8 | 49.87 (14) | Cs1—O6—As2 | 127.8 (2) |
O7—Cs2—O3 | 100.09 (17) | Cs1—O6—Ti1 | 97.14 (19) |
O7—Cs2—O12 | 84.30 (16) | Cs3—O6—As2 | 127.1 (3) |
O7—Cs2—O1i | 73.73 (19) | Cs3—O6—Ti1 | 97.2 (3) |
O7—Cs2—O5 | 128.30 (18) | As2—O6—Ti1 | 134.9 (3) |
O2—Cs2—O8 | 63.91 (17) | Cs1—O7—Cs2 | 90.85 (16) |
O2—Cs2—O3 | 47.36 (14) | Cs1—O7—Ti2 | 87.38 (17) |
O2—Cs2—O12 | 94.68 (18) | Cs1—O7—As2 | 95.5 (2) |
O2—Cs2—O1i | 51.20 (15) | Cs1—O7—Cs4 | 87.4 (3) |
O2—Cs2—O5 | 52.18 (15) | Cs2—O7—Ti2 | 135.4 (3) |
O8—Cs2—O3 | 51.03 (14) | Cs2—O7—As2 | 96.0 (2) |
O8—Cs2—O12 | 48.94 (14) | Cs2—O7—Cs4 | 4.9 (3) |
O8—Cs2—O1i | 91.02 (18) | Ti2—O7—As2 | 128.5 (3) |
O8—Cs2—O5 | 115.6 (2) | Ti2—O7—Cs4 | 131.7 (4) |
O3—Cs2—O12 | 50.88 (14) | As2—O7—Cs4 | 99.7 (4) |
O3—Cs2—O1i | 98.42 (17) | Cs1—O8—Cs3 | 7.12 (15) |
O3—Cs2—O5 | 78.64 (16) | Cs1—O8—Ti2 | 113.9 (2) |
O12—Cs2—O1i | 138.6 (2) | Cs1—O8—Cs2 | 100.6 (2) |
O12—Cs2—O5 | 125.7 (2) | Cs1—O8—As2 | 108.9 (2) |
O1i—Cs2—O5 | 55.82 (17) | Cs1—O8—Cs4 | 101.0 (3) |
O1—Ti1—O11 | 84.0 (2) | Cs3—O8—Ti2 | 120.3 (3) |
O1—Ti1—O5 | 81.4 (2) | Cs3—O8—Cs2 | 95.7 (3) |
O1—Ti1—O2 | 83.0 (2) | Cs3—O8—As2 | 103.6 (3) |
O1—Ti1—O6 | 85.4 (2) | Cs3—O8—Cs4 | 96.0 (4) |
O1—Ti1—O12 | 172.7 (2) | Ti2—O8—Cs2 | 100.7 (2) |
O11—Ti1—O5 | 94.9 (2) | Ti2—O8—As2 | 133.8 (3) |
O11—Ti1—O2 | 166.4 (2) | Ti2—O8—Cs4 | 102.9 (3) |
O11—Ti1—O6 | 87.6 (2) | Cs2—O8—As2 | 87.6 (2) |
O11—Ti1—O12 | 97.9 (2) | Cs2—O8—Cs4 | 2.8 (3) |
O5—Ti1—O2 | 87.0 (2) | As2—O8—Cs4 | 84.9 (3) |
O5—Ti1—O6 | 166.2 (2) | Cs1—Cs3—O2 | 90 (2) |
O5—Ti1—O12 | 91.4 (2) | Cs1—Cs3—O3 | 74 (2) |
O2—Ti1—O6 | 87.4 (2) | Cs1—Cs3—O12 | 90 (2) |
O2—Ti1—O12 | 95.6 (2) | Cs1—Cs3—O5 | 9 (2) |
O6—Ti1—O12 | 101.8 (2) | Cs1—Cs3—O6 | 114 (2) |
O3—Ti2—O12 | 86.3 (2) | Cs1—Cs3—O8 | 84 (2) |
O3—Ti2—O7 | 86.9 (2) | O2—Cs3—O3 | 136.2 (5) |
O3—Ti2—O4i | 173.8 (2) | O2—Cs3—O12 | 165.2 (6) |
O3—Ti2—O11 | 92.1 (2) | O2—Cs3—O5 | 91.5 (3) |
O3—Ti2—O8 | 90.4 (2) | O2—Cs3—O6 | 56.1 (3) |
O12—Ti2—O7 | 86.0 (2) | O2—Cs3—O8 | 74.5 (3) |
O12—Ti2—O4i | 87.5 (2) | O3—Cs3—O12 | 57.6 (3) |
O12—Ti2—O11 | 177.3 (2) | O3—Cs3—O5 | 67.3 (2) |
O12—Ti2—O8 | 84.1 (2) | O3—Cs3—O6 | 93.1 (4) |
O7—Ti2—O4i | 92.6 (2) | O3—Cs3—O8 | 140.6 (5) |
O7—Ti2—O11 | 96.1 (2) | O12—Cs3—O5 | 90.9 (3) |
O7—Ti2—O8 | 169.9 (2) | O12—Cs3—O6 | 136.3 (4) |
O4i—Ti2—O11 | 94.1 (2) | O12—Cs3—O8 | 90.8 (4) |
O4i—Ti2—O8 | 89.1 (2) | O5—Cs3—O6 | 108.0 (4) |
O11—Ti2—O8 | 93.8 (2) | O5—Cs3—O8 | 92.6 (3) |
O1—As1—O2 | 108.6 (3) | O6—Cs3—O8 | 125.9 (4) |
O1—As1—O3 | 110.6 (3) | Cs2—Cs4—O4 | 126 (4) |
O1—As1—O4 | 110.7 (3) | Cs2—Cs4—O11 | 98 (4) |
O2—As1—O3 | 105.1 (3) | Cs2—Cs4—O7 | 84 (4) |
O2—As1—O4 | 109.6 (3) | Cs2—Cs4—O2 | 41 (3) |
O3—As1—O4 | 112.0 (2) | Cs2—Cs4—O8 | 38 (3) |
O5—As2—O7 | 106.8 (3) | Cs2—Cs4—O3 | 11 (3) |
O5—As2—O6 | 115.4 (3) | Cs2—Cs4—O12 | 48 (3) |
O5—As2—O8 | 109.5 (3) | Cs2—Cs4—O1i | 88 (4) |
O7—As2—O6 | 110.8 (2) | Cs2—Cs4—O5 | 79 (4) |
O7—As2—O8 | 104.4 (3) | O4—Cs4—O11 | 57.4 (3) |
O6—As2—O8 | 109.4 (3) | O4—Cs4—O7 | 135.2 (6) |
Cs1—O1—Ti1 | 96.8 (2) | O4—Cs4—O2 | 139.5 (6) |
Cs1—O1—As1 | 84.7 (2) | O4—Cs4—O8 | 140.6 (6) |
Cs1—O1—Cs2 | 81.12 (17) | O4—Cs4—O3 | 115.7 (5) |
Cs1—O1—Cs4 | 76.9 (4) | O4—Cs4—O12 | 95.0 (4) |
Ti1—O1—As1 | 133.1 (4) | O4—Cs4—O1i | 132.3 (6) |
Ti1—O1—Cs2 | 104.5 (2) | O4—Cs4—O5 | 94.8 (5) |
Ti1—O1—Cs4 | 107.9 (4) | O11—Cs4—O7 | 88.8 (5) |
As1—O1—Cs2 | 121.9 (3) | O11—Cs4—O2 | 138.9 (6) |
As1—O1—Cs4 | 117.9 (5) | O11—Cs4—O8 | 86.5 (4) |
Cs2—O1—Cs4 | 5.2 (4) | O11—Cs4—O3 | 96.1 (5) |
Cs1—O2—As1 | 104.4 (3) | O11—Cs4—O12 | 50.5 (3) |
Cs1—O2—Cs3 | 7.37 (16) | O11—Cs4—O1i | 160.7 (7) |
Cs1—O2—Ti1 | 117.4 (3) | O11—Cs4—O5 | 143.8 (6) |
Cs1—O2—Cs2 | 101.5 (2) | O7—Cs4—O2 | 85.2 (4) |
Cs1—O2—Cs4 | 102.2 (3) | O7—Cs4—O8 | 47.7 (3) |
As1—O2—Cs3 | 111.4 (3) | O7—Cs4—O3 | 94.4 (4) |
As1—O2—Ti1 | 132.1 (4) | O7—Cs4—O12 | 81.2 (4) |
As1—O2—Cs2 | 101.2 (3) | O7—Cs4—O1i | 73.5 (4) |
As1—O2—Cs4 | 103.8 (4) | O7—Cs4—O5 | 126.2 (5) |
Cs3—O2—Ti1 | 111.8 (3) | O2—Cs4—O8 | 59.9 (3) |
Cs3—O2—Cs2 | 97.4 (3) | O2—Cs4—O3 | 44.2 (2) |
Cs3—O2—Cs4 | 97.8 (4) | O2—Cs4—O12 | 88.4 (4) |
Ti1—O2—Cs2 | 92.76 (19) | O2—Cs4—O1i | 48.8 (3) |
Ti1—O2—Cs4 | 89.9 (3) | O2—Cs4—O5 | 49.9 (3) |
Cs2—O2—Cs4 | 2.9 (3) | O8—Cs4—O3 | 47.5 (3) |
Cs1—O3—Ti2 | 102.8 (2) | O8—Cs4—O12 | 46.2 (3) |
Cs1—O3—Cs3 | 6.99 (17) | O8—Cs4—O1i | 87.0 (4) |
Cs1—O3—As1 | 127.5 (3) | O8—Cs4—O5 | 109.1 (5) |
Cs1—O3—Cs2 | 76.18 (14) | O3—Cs4—O12 | 47.6 (3) |
Cs1—O3—Cs4 | 75.5 (3) | O3—Cs4—O1i | 92.9 (5) |
Ti2—O3—Cs3 | 104.2 (3) | O3—Cs4—O5 | 74.2 (4) |
Ti2—O3—As1 | 129.3 (3) | O12—Cs4—O1i | 131.0 (6) |
Ti2—O3—Cs2 | 96.89 (19) | O12—Cs4—O5 | 118.9 (5) |
Ti2—O3—Cs4 | 97.4 (3) | O1i—Cs4—O5 | 55.4 (3) |
Cs3—O3—As1 | 126.5 (4) | | |
Symmetry code: (i) x+1/2, −y+1/2, z. |
Crystal data top
CsTiOAsO4 | F(000) = 1200 |
Mr = 335.7 | Dx = 4.517 Mg m−3 |
Orthorhombic, Pna21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2c -2n | Cell parameters from 6293 reflections |
a = 13.4623 (1) Å | θ = 3.0–45.4° |
b = 6.8484 (1) Å | µ = 15.58 mm−1 |
c = 10.7075 (1) Å | T = 183 K |
V = 987.18 (2) Å3 | Rectangular, colourless |
Z = 8 | 0.03 × 0.02 × 0.02 mm |
Data collection top
Siemens SMART CCD diffractometer | 6940 independent reflections |
Radiation source: fine-focus sealed tube | 4282 reflections with F2 > 2σ(F2) |
Graphite monochromator | Rint = 0.087 |
ω scans | θmax = 45.4°, θmin = 3.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −26→25 |
Tmin = 0.65, Tmax = 0.75 | k = −13→13 |
30621 measured reflections | l = −16→21 |
Refinement top
Refinement on F | 1/σ2 |
Least-squares matrix: full | (Δ/σ)max = 0.008 |
R[F2 > 2σ(F2)] = 0.043 | Δρmax = 2.54 e Å−3 |
wR(F2) = 0.03 | Δρmin = −2.69 e Å−3 |
S = 1.88 | Extinction correction: Zachariasen (1968), Eq22 p292 "Cryst. Comp." Munksgaard 1970 |
4282 reflections | Extinction coefficient: 473 (26) |
144 parameters | Absolute structure: Flack (1983) |
0 restraints | Absolute structure parameter: 0.06 (2) |
0 constraints | |
Crystal data top
CsTiOAsO4 | V = 987.18 (2) Å3 |
Mr = 335.7 | Z = 8 |
Orthorhombic, Pna21 | Mo Kα radiation |
a = 13.4623 (1) Å | µ = 15.58 mm−1 |
b = 6.8484 (1) Å | T = 183 K |
c = 10.7075 (1) Å | 0.03 × 0.02 × 0.02 mm |
Data collection top
Siemens SMART CCD diffractometer | 6940 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 4282 reflections with F2 > 2σ(F2) |
Tmin = 0.65, Tmax = 0.75 | Rint = 0.087 |
30621 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.043 | 0 restraints |
wR(F2) = 0.03 | Δρmax = 2.54 e Å−3 |
S = 1.88 | Δρmin = −2.69 e Å−3 |
4282 reflections | Absolute structure: Flack (1983) |
144 parameters | Absolute structure parameter: 0.06 (2) |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Cs1 | 0.61358 (4) | 0.21495 (6) | 0.3742 (4) | 0.0124 (2) | |
Cs2 | 0.88981 (4) | 0.30429 (6) | 0.1165 (4) | 0.0096 (2) | |
Ti1 | 0.62756 (8) | 0.4964 (2) | 0.0263 (4) | 0.0041 (5) | |
Ti2 | 0.74947 (11) | 0.73307 (17) | 0.2770 (4) | 0.0038 (5) | |
As1 | 0.49933 (6) | 0.67332 (9) | 0.2828 (4) | 0.0035 (2) | |
As2 | 0.82191 (5) | 0.49766 (12) | 0.5375 (4) | 0.0039 (2) | |
O1 | 0.5144 (5) | 0.5217 (9) | 0.1631 (6) | 0.008 (3) | |
O2 | 0.4859 (5) | 0.5408 (9) | 0.4147 (6) | 0.008 (3) | |
O3 | 0.6030 (4) | 0.8078 (7) | 0.3074 (6) | 0.006 (2) | |
O4 | 0.3986 (5) | 0.8164 (7) | 0.2619 (6) | 0.008 (2) | |
O11 | 0.7170 (4) | 0.5572 (7) | 0.1660 (6) | 0.006 (2) | |
O12 | 0.7832 (5) | 0.9431 (8) | 0.4166 (5) | 0.006 (1) | |
O5 | 0.8880 (5) | 0.6978 (7) | 0.5742 (6) | 0.008 (2) | |
O6 | 0.8898 (4) | 0.2982 (7) | 0.5021 (6) | 0.008 (2) | |
O7 | 0.7460 (4) | 0.4527 (8) | 0.6607 (5) | 0.007 (2) | |
O8 | 0.7442 (5) | 0.5490 (8) | 0.417 (1) | 0.009 (1) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cs1 | 0.0103 (3) | 0.00564 (17) | 0.0214 (3) | 0.00157 (16) | −0.0031 (2) | −0.00195 (18) |
Cs2 | 0.0063 (2) | 0.00729 (16) | 0.0152 (2) | 0.00166 (16) | −0.0009 (2) | −0.00199 (18) |
Ti1 | 0.0041 (5) | 0.0054 (4) | 0.0029 (5) | −0.0000 (5) | 0.0003 (4) | −0.0003 (4) |
Ti2 | 0.0042 (5) | 0.0036 (4) | 0.0036 (5) | −0.0007 (4) | −0.0004 (5) | −0.0002 (5) |
As1 | 0.0034 (3) | 0.0038 (2) | 0.0032 (3) | 0.0002 (3) | −0.0000 (3) | 0.0001 (2) |
As2 | 0.0042 (3) | 0.0035 (2) | 0.0039 (2) | −0.0003 (3) | 0.0001 (3) | 0.0003 (2) |
O1 | 0.005 (3) | 0.010 (2) | 0.009 (3) | −0.000 (2) | 0.0004 (18) | −0.0030 (18) |
O2 | 0.008 (3) | 0.009 (2) | 0.007 (3) | 0.002 (2) | 0.0011 (18) | 0.0044 (17) |
O3 | 0.002 (2) | 0.007 (2) | 0.010 (3) | −0.001 (2) | 0.0000 (18) | −0.0003 (18) |
O4 | 0.008 (3) | 0.004 (2) | 0.012 (3) | 0.000 (2) | −0.004 (2) | 0.0003 (18) |
O11 | 0.006 (2) | 0.004 (2) | 0.009 (2) | 0.0008 (18) | 0.0008 (19) | −0.0000 (16) |
O12 | 0.006 (1) | 0.006 (1) | 0.006 (1) | 0 | 0 | 0 |
O5 | 0.013 (3) | 0.0039 (19) | 0.007 (2) | −0.003 (2) | −0.002 (2) | −0.0009 (17) |
O6 | 0.007 (2) | 0.005 (2) | 0.012 (3) | −0.001 (2) | 0.003 (2) | −0.0003 (18) |
O7 | 0.007 (3) | 0.010 (2) | 0.005 (2) | 0.003 (2) | −0.0006 (18) | 0.0029 (17) |
O8 | 0.009 (1) | 0.009 (1) | 0.009 (1) | 0 | 0 | 0 |
Geometric parameters (Å, º) top
Cs1—O1 | 3.362 (7) | Ti1—O11 | 1.964 (7) |
Cs1—O2 | 2.850 (6) | Ti1—O5 | 2.119 (5) |
Cs1—O3 | 2.882 (5) | Ti1—O2 | 1.955 (7) |
Cs1—O11 | 3.521 (6) | Ti1—O6 | 2.096 (5) |
Cs1—O12 | 2.9813 (8) | Ti1—O12 | 1.719 (3) |
Cs1—O5 | 3.214 (8) | Ti2—O3 | 2.063 (6) |
Cs1—O6 | 3.310 (6) | Ti2—O12 | 2.124 (3) |
Cs1—O7 | 3.468 (6) | Ti2—O7 | 1.953 (6) |
Cs1—O8 | 2.9224 (8) | Ti2—O4i | 2.042 (6) |
Cs2—O4 | 3.031 (6) | Ti2—O11 | 1.748 (6) |
Cs2—O11 | 2.949 (6) | Ti2—O8 | 1.963 (3) |
Cs2—O7 | 3.060 (5) | As1—O1 | 1.662 (7) |
Cs2—O2 | 3.275 (7) | As1—O2 | 1.689 (7) |
Cs2—O8 | 3.296 (2) | As1—O3 | 1.693 (5) |
Cs2—O3 | 3.312 (8) | As1—O4 | 1.688 (6) |
Cs2—O12 | 3.304 (2) | As2—O5 | 1.681 (6) |
Cs2—O1i | 2.837 (6) | As2—O7 | 1.697 (6) |
Cs2—O5 | 3.025 (6) | As2—O6 | 1.687 (6) |
Ti1—O1 | 2.120 (7) | As2—O8 | 1.695 (3) |
| | | |
O1—Cs1—O2 | 51.22 (17) | O3—Ti2—O7 | 86.5 (2) |
O1—Cs1—O3 | 114.7 (2) | O3—Ti2—O8 | 90.2 (2) |
O1—Cs1—O12 | 142.81 (15) | O3—Ti2—O4i | 173.3 (3) |
O1—Cs1—O5 | 49.33 (15) | O3—Ti2—O11 | 92.2 (3) |
O1—Cs1—O6 | 86.20 (15) | O12—Ti2—O7 | 85.45 (17) |
O1—Cs1—O7 | 95.56 (17) | O12—Ti2—O8 | 84.48 (15) |
O1—Cs1—O8 | 81.72 (11) | O12—Ti2—O4i | 87.56 (18) |
O2—Cs1—O3 | 139.94 (17) | O12—Ti2—O11 | 177.4 (2) |
O2—Cs1—O12 | 158.10 (17) | O7—Ti2—O8 | 169.6 (2) |
O2—Cs1—O5 | 100.18 (18) | O7—Ti2—O4i | 92.7 (3) |
O2—Cs1—O6 | 53.80 (16) | O7—Ti2—O11 | 96.0 (3) |
O2—Cs1—O7 | 146.6 (2) | O8—Ti2—O4i | 89.37 (19) |
O2—Cs1—O8 | 74.12 (13) | O8—Ti2—O11 | 93.9 (2) |
O3—Cs1—O5 | 73.51 (17) | O4i—Ti2—O11 | 94.5 (3) |
O3—Cs1—O6 | 91.79 (14) | O1—As1—O2 | 108.8 (3) |
O3—Cs1—O7 | 50.38 (15) | O1—As1—O3 | 111.0 (3) |
O3—Cs1—O8 | 145.71 (11) | O1—As1—O4 | 111.0 (4) |
O12—Cs1—O5 | 97.73 (13) | O2—As1—O3 | 104.5 (3) |
O12—Cs1—O6 | 128.12 (13) | O2—As1—O4 | 109.7 (3) |
O12—Cs1—O7 | 50.16 (10) | O3—As1—O4 | 111.6 (3) |
O12—Cs1—O8 | 90.20 (3) | O5—As2—O7 | 106.6 (3) |
O5—Cs1—O6 | 113.96 (17) | O5—As2—O6 | 115.2 (3) |
O5—Cs1—O7 | 47.62 (15) | O5—As2—O8 | 109.6 (2) |
O5—Cs1—O8 | 100.98 (13) | O7—As2—O6 | 110.7 (3) |
O6—Cs1—O7 | 138.99 (14) | O7—As2—O8 | 104.9 (2) |
O6—Cs1—O8 | 120.26 (12) | O6—As2—O8 | 109.4 (3) |
O7—Cs1—O8 | 100.45 (10) | Cs1—O1—Ti1 | 97.4 (2) |
O3—Cs2—O4 | 120.40 (16) | Cs1—O1—As1 | 85.4 (3) |
O3—Cs2—O11 | 101.44 (17) | Cs1—O1—Cs2 | 82.02 (16) |
O3—Cs2—O12 | 51.02 (11) | Ti1—O1—As1 | 132.2 (4) |
O3—Cs2—O2 | 47.90 (15) | Ti1—O1—Cs2 | 103.8 (2) |
O3—Cs2—O8 | 51.17 (10) | As1—O1—Cs2 | 123.7 (3) |
O3—Cs2—O1 | 99.44 (18) | Cs1—O2—As1 | 103.2 (3) |
O3—Cs2—O5 | 79.71 (17) | Cs1—O2—Cs2 | 102.9 (2) |
O3—Cs2—O7 | 100.23 (16) | Cs1—O2—Ti1 | 117.5 (3) |
O4—Cs2—O11 | 55.60 (16) | As1—O2—Cs2 | 101.6 (3) |
O4—Cs2—O12 | 96.52 (12) | As1—O2—Ti1 | 131.7 (4) |
O4—Cs2—O2 | 142.30 (16) | Cs2—O2—Ti1 | 93.9 (2) |
O4—Cs2—O8 | 143.94 (12) | Cs1—O3—Cs2 | 75.96 (16) |
O4—Cs2—O1 | 124.1 (2) | Cs1—O3—Ti2 | 103.4 (2) |
O4—Cs2—O5 | 92.43 (16) | Cs1—O3—As1 | 127.3 (3) |
O4—Cs2—O7 | 128.20 (19) | Cs2—O3—Ti2 | 97.4 (2) |
O11—Cs2—O2 | 147.7 (2) | Cs2—O3—As1 | 100.1 (3) |
O11—Cs2—O8 | 89.75 (12) | Ti2—O3—As1 | 129.0 (3) |
O11—Cs2—O1 | 153.8 (2) | Cs2—O4—As1 | 126.6 (3) |
O11—Cs2—O5 | 144.08 (14) | Cs2—O4—Ti2 | 98.3 (2) |
O11—Cs2—O7 | 87.88 (15) | As1—O4—Ti2 | 133.1 (3) |
O12—Cs2—O2 | 95.25 (15) | Cs2—O11—Ti1 | 102.8 (2) |
O12—Cs2—O8 | 49.25 (4) | Cs2—O11—Ti2 | 109.2 (3) |
O12—Cs2—O1 | 139.24 (16) | Ti1—O11—Ti2 | 144.8 (3) |
O12—Cs2—O5 | 126.98 (16) | Cs1—O12—Cs2 | 74.82 (6) |
O12—Cs2—O7 | 84.57 (11) | Cs1—O12—Ti2 | 98.72 (7) |
O2—Cs2—O8 | 63.93 (13) | Cs1—O12—Ti1 | 120.45 (7) |
O2—Cs2—O1 | 51.69 (17) | Cs2—O12—Ti2 | 96.32 (8) |
O2—Cs2—O5 | 52.66 (16) | Cs2—O12—Ti1 | 96.37 (11) |
O2—Cs2—O7 | 88.49 (16) | Ti2—O12—Ti1 | 140.74 (7) |
O8—Cs2—O1 | 91.15 (13) | Cs1—O5—Ti1 | 101.9 (2) |
O8—Cs2—O5 | 116.23 (14) | Cs1—O5—As2 | 105.1 (3) |
O8—Cs2—O7 | 49.87 (11) | Cs1—O5—Cs2 | 81.79 (17) |
O1—Cs2—O5 | 55.81 (16) | Ti1—O5—As2 | 132.7 (4) |
O1—Cs2—O7 | 72.95 (17) | Ti1—O5—Cs2 | 98.0 (2) |
O5—Cs2—O7 | 127.60 (14) | As2—O5—Cs2 | 123.7 (3) |
O1—Ti1—O5 | 80.8 (3) | Cs1—O6—As2 | 127.5 (3) |
O1—Ti1—O2 | 82.6 (3) | Cs1—O6—Ti1 | 97.2 (2) |
O1—Ti1—O6 | 85.7 (2) | As2—O6—Ti1 | 135.2 (4) |
O1—Ti1—O11 | 84.1 (3) | Cs1—O7—Ti2 | 87.8 (2) |
O1—Ti1—O12 | 172.44 (18) | Cs1—O7—As2 | 95.2 (2) |
O5—Ti1—O2 | 86.8 (3) | Cs1—O7—Cs2 | 91.14 (14) |
O5—Ti1—O6 | 166.1 (3) | Ti2—O7—As2 | 128.1 (3) |
O5—Ti1—O11 | 94.6 (3) | Ti2—O7—Cs2 | 136.3 (3) |
O5—Ti1—O12 | 91.72 (19) | As2—O7—Cs2 | 95.6 (2) |
O2—Ti1—O6 | 88.0 (3) | Cs1—O8—Cs2 | 100.82 (5) |
O2—Ti1—O11 | 166.2 (3) | Cs1—O8—Ti2 | 113.79 (9) |
O2—Ti1—O12 | 95.8 (3) | Cs1—O8—As2 | 109.20 (6) |
O6—Ti1—O11 | 87.3 (2) | Cs2—O8—Ti2 | 100.03 (8) |
O6—Ti1—O12 | 101.7 (2) | Cs2—O8—As2 | 87.50 (9) |
O11—Ti1—O12 | 97.89 (18) | Ti2—O8—As2 | 133.83 (7) |
O3—Ti2—O12 | 85.73 (19) | | |
Symmetry code: (i) x+1/2, −y+1/2, z. |
Experimental details
| (I) | (II) | (III) |
Crystal data |
Chemical formula | CsTiOAsO4 | CsTiOAsO4 | CsTiOAsO4 |
Mr | 335.7 | 335.7 | 335.7 |
Crystal system, space group | Orthorhombic, Pna21 | Orthorhombic, Pna21 | Orthorhombic, Pna21 |
Temperature (K) | 297 | 297 | 183 |
a, b, c (Å) | 13.4892 (3), 6.8637 (1), 10.6908 (1) | 13.4892 (3), 6.8637 (1), 10.6908 (1) | 13.4623 (1), 6.8484 (1), 10.7075 (1) |
V (Å3) | 989.82 (3) | 989.82 (3) | 987.18 (2) |
Z | 8 | 8 | 8 |
Radiation type | Mo Kα | Mo Kα | Mo Kα |
µ (mm−1) | 15.54 | 15.54 | 15.58 |
Crystal size (mm) | 0.03 × 0.02 × 0.02 | 0.03 × 0.02 × 0.02 | 0.03 × 0.02 × 0.02 |
|
Data collection |
Diffractometer | Siemens SMART CCD diffractometer | Siemens SMART CCD diffractometer | Siemens SMART CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) | Multi-scan (SADABS; Sheldrick, 1996) | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.65, 0.75 | 0.65, 0.75 | 0.65, 0.75 |
No. of measured, independent and observed reflections | 36263, 6720, 4208 [F2 > 3σ(F2)] | 36263, 6720, 4208 [F2 > 3σ(F2)] | 30621, 6940, 4282 [F2 > 2σ(F2)] |
Rint | 0.078 | 0.078 | 0.087 |
(sin θ/λ)max (Å−1) | 0.937 | 0.937 | 1.001 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.026, 1.89 | 0.034, 0.023, 1.73 | 0.043, 0.03, 1.88 |
No. of reflections | 4208 | 4208 | 4282 |
No. of parameters | 146 | 164 | 144 |
Δρmax, Δρmin (e Å−3) | 3.14, −2.39 | 1.41, −1.26 | 2.54, −2.69 |
Absolute structure | Flack (1983) | Flack (1983) | Flack (1983) |
Absolute structure parameter | 0.05 (2) | 0.05 (2) | 0.06 (2) |
Selected bond lengths (Å) for (II) topCs1—O1 | 3.408 (6) | Cs2—O5 | 3.036 (7) |
Cs1—O2 | 2.851 (7) | Cs2—Cs4 | 0.260 (18) |
Cs1—O3 | 2.893 (6) | Cs3—O2 | 2.826 (15) |
Cs1—O11 | 3.528 (6) | Cs3—O3 | 2.972 (13) |
Cs1—O12 | 2.983 (7) | Cs3—O12 | 2.961 (15) |
Cs1—O5 | 3.233 (5) | Cs3—O5 | 3.594 (9) |
Cs1—O6 | 3.303 (7) | Cs3—O6 | 3.136 (15) |
Cs1—O7 | 3.473 (6) | Cs3—O8 | 2.952 (15) |
Cs1—O8 | 2.934 (7) | Cs4—O4 | 2.885 (16) |
Cs1—Cs3 | 0.366 (8) | Cs4—O11 | 2.926 (17) |
Cs2—O4 | 3.043 (6) | Cs4—O7 | 3.057 (17) |
Cs2—O11 | 2.974 (7) | Cs4—O2 | 3.515 (17) |
Cs2—O7 | 3.041 (6) | Cs4—O8 | 3.49 (2) |
Cs2—O2 | 3.323 (7) | Cs4—O3 | 3.594 (17) |
Cs2—O8 | 3.287 (7) | Cs4—O12 | 3.486 (17) |
Cs2—O3 | 3.339 (7) | Cs4—O1i | 2.837 (17) |
Cs2—O12 | 3.318 (7) | Cs4—O5 | 3.076 (17) |
Cs2—O1i | 2.838 (7) | | |
Symmetry code: (i) x+1/2, −y+1/2, z. |
Selected bond lengths (Å) for (III) topCs1—O1 | 3.362 (7) | Cs2—O4 | 3.031 (6) |
Cs1—O2 | 2.850 (6) | Cs2—O11 | 2.949 (6) |
Cs1—O3 | 2.882 (5) | Cs2—O7 | 3.060 (5) |
Cs1—O11 | 3.521 (6) | Cs2—O2 | 3.275 (7) |
Cs1—O12 | 2.9813 (8) | Cs2—O8 | 3.296 (2) |
Cs1—O5 | 3.214 (8) | Cs2—O3 | 3.312 (8) |
Cs1—O6 | 3.310 (6) | Cs2—O12 | 3.304 (2) |
Cs1—O7 | 3.468 (6) | Cs2—O1i | 2.837 (6) |
Cs1—O8 | 2.9224 (8) | Cs2—O5 | 3.025 (6) |
Symmetry code: (i) x+1/2, −y+1/2, z. |
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Caesium titanyl arsenate, CTA, belongs to the KTiOPO4 (KTP) isomorphic family of compounds, known for their excellent ferroelectric and non-linear optical properties (Stucky et al., 1989). Arsenates such as RbTiOAsO4 (RTA) and CTA have high transmission in the IR region, superior to that of KTP, and this property can be used to extend the optical range of lasers (Mangin et al., 1989).
The general structure in CTA is a three-dimensional network of AsO4 tetrahedra and distorted TiO6 octahedra, with periodic bond chains of –AsO4—TiO6—AsO4—TiO6 along the a and b directions and the ac diagonal (Protas et al., 1989). In the octahedra, the Ti atoms are displaced, giving alternating shorter (Ti1—O12 and Ti2—O11) and longer (Ti2—O12 and Ti1—O11) bonds along the polar c axis. The three-dimensional network has open channels along c, with two different sites for the Cs cations. The ferroelectric phase transition for KTP isomorphs is continuous second order of both displacive and order-disorder type (Belokoneva et al., 1997). During the transformation from the paraelectric to the ferroelectric phase, the cations are displaced along the polarization vector to two independent sites. However, elements of the high temperature structure are retained at room temperature (Thomas et al., 1990; Thomas & Womersley, 1998).
Womersley et al. (1998) have reported some evidence of disorder of the cations over additional sites along the c direction for Cs-rich compounds of CsxRb1 - xTiOAsO4 mixtures. Split alkaline positions had previously been refined for KFeFPO4 at room temperature (Belokoneva et al., 1990). The KTP and RbTiOPO4 (RTP) structures have been studied at elevated temperatures by Delarue et al. (1998, 1999). The split cation sites model could be applied at temperatures higher than 473 K. For RTA, additional density at the Rb sites was noted in the 9.6 K structure but refinement of the split positions model was not applicable (Almgren et al., 1999). Recently, synchrotron data at room temperature by Streltsov et al. (2000) has shown that a combination of split Rb positions and multipole functions in the refinement gives the best description of the RTA structure. The question has been posed as to whether the split alkaline positions are universal for KTP isomorphs. Thus, it was desirable to conduct an accurate X-ray diffraction study of the CTA structure to investigate the status of the Cs positions and how these would change with temperature.
Flack parameter refinements (see below) indicated that a single-domain crystal was used. Model I, with two fully occupied Cs sites, was first refined for the room temperature structure. It resulted in significant residual electron density found along the c direction at both Cs sites at a distance of approximately 0.67 and 0.75 Å from Cs1 and Cs2, respectively. The use of Model II, with split Cs positions, resulted in a better fit of the refined structure to experimental data and significantly reduced the excess electron density around the Cs atoms. The refined positions were found closer to the original Cs positions than the additional density resulting from the Model I refinement. The new Cs3 atom was positioned 0.366 (8) Å from Cs1 along the c axis. For the Cs2—Cs4 couple, the corresponding distance was 0.26 (2) Å. This could be compared with the interatomic distances in the a and b directions, which were an order of magnitude shorter. The occupancies of the split Cs positions were 0.800 (7) for Cs1 and 0.200 (7) for Cs3, and 0.80 (1) for Cs2 and 0.20 (1) for Cs4. This could be compared with the RTA room temperature structure, where the Rb1 site has an occupancy of 0.885 (5) and Rb2 an occupancy of 0.872 (9). The shifts of the additional Rb positions are 0.303 (2) and 0.228 (3) Å for the Rb1—Rb3 and Rb2—Rb4 pairs, respectively (Streltsov et al., 2000). In RTP at 473 K the corresponding distances are 0.27 (1) and 0.19 (1) Å. It could therefore be concluded that the splitting is more pronounced in CTA than in the KTP isomorphs previously re-investigated.
An ORTEP plot (Johnson et al., 1972) of the room temperature structure in the ac plane is given in Fig. 1. The elongated isotropic displacement ellipsoid of Cs4 indicates that this additional site is in fact not one position but represents several Cs positions which cannot be resolved. The isotropic displacement parameters along the principal axes have been calculated using the program ORFFE modified for PC (Busing et al., 1964; Gustafsson, 1993). For Cs4, the isotropic displacements along the principal axes r1, r2 and r3 were 0.06 (3), 0.13 (1) and 0.24?(1) Å, respectively. The corresponding values for Cs2 were 0.093 (3), 0.107 (3) and 0.155 (3) Å, respectively. The r.m.s. parameters were more uniform for the Cs1—Cs3 pair, with displacements along r1 and r3 of 0.095 (1) and 0.172 (2), respectively, for Cs1, and 0.085 (9) and 0.17 (1) Å, respectively, for Cs3. The Cs1 and Cs2 atoms vibrate predominately in the [001] direction with an angle to the c axis of 25 (5)°. Atoms Cs3 and Cs4 also vibrate mainly in this direction. This is correlated with the coordination of the Cs sites situated in the channels along c and with no oxygen bonds in the [001] direction.
At 183 K, the residual electron density near the Cs atoms could not be resolved to any specific split positions and for this temperature Model I was used in the refinement. The atomic coordinates for Cs1 and Cs2 were very similar to the coordinates for the same atoms at room temperature. This indicates that the additional Cs peaks have moved towards the dominant Cs sites. It should be noted that in the refinement of the room temperature structure using Model I, the fractional z coordinates of Cs1 and Cs2 were in between those of the Cs1—Cs3 and Cs2—Cs4 pairs in Model II. For the RTA structure on the other hand, the average z coordinates at room temperature of Rb1—Rb3 and Rb2—Rb4, respectively (Streltsov et al., 2000), corresponded well with the 9.6 K coordinates of Rb1 and Rb2 (Almgren et al., 1999). The thermal displacements along the principal axes r1, r2 and r3 were 0.073 (2), 0.100 (1) and 0.150 (1) Å, respectively, for Cs1, and 0.072 (2), 0.091 (1) and 0.1255 (8) Å, respectively, for Cs2, at 183 K. Both cations vibrated in the [001] direction with an angle of 18 (1)° to the c axis.
The original Cs sites are coordinated by nine O atoms and this is also true for the additional Cs4 site. Cs3 is, on the other hand, coordinated by six O atoms; selected atomic bond distances are given in Table 1. The three-dimensional network structure was little affected by the inclusion of additional Cs positions at room temperature. No significant differences were noted in the bond lengths, neither in the Ti octahedra nor in the As tetrahedra. As the Cs1 and Cs2 sites at room temperature correspond to those at 183 K, the Cs1—O and Cs2—O bonds did not change significantly with temperature (Table 2).