The structure of moganite-type phosphorus oxynitride quenched from high-pressure high-temperature conditions has been refined using neutron powder diffraction data. This moganite-type structure, space group I2/a, Z = 12, is slightly less distorted with respect to the Imab aristotype than is moganite (a monoclinic form of silica). A close topological relationship has been identified between the moganite-type and orthorhombic BeH2 structures indicating that SiO2, PON and BeH2 all adopt structures belonging to the twinned-quartz-based group. This group represents another possible structure type for systems composed of corner-sharing AX4 tetrahedra. Structures of this group are obvious candidates for intermediate phases between the cristobalite and quartz types.
Supporting information
| Crystallographic Information File (CIF) Contains datablocks global, PON |
| Rietveld powder data file (CIF format) Supplementary material |
Program(s) used to refine structure: GSAS (Larson and Von Dreele, 1994).
phosphorus oxynitride
top
Crystal data top
NOP | V = 420.27 (1) Å3 |
Mr = 60.98 | Z = 12 |
Monoclinic, I2/a | Neutron radiation, λ = ? Å |
Hall symbol: -I 2ya | T = 298 K |
a = 8.5194 (2) Å | grey |
b = 4.7448 (1) Å | cylinder, ? × ? × ? mm |
c = 10.3970 (3) Å | Specimen preparation: Prepared at 1158-1173 K and 2500000 kPa, cooled at 18000 K min−1 |
β = 90.013 (6)° | |
Data collection top
Polaris medium resolution diffractometer | Specimen mounting: silica tube |
Radiation source: ISIS spallation source | Data collection mode: transmission |
Refinement top
Rp = 0.110 | Profile function: type 3 time-of-flight profile function [pseudo-voigt convoluted, with back-to-back exponentials (Larson and Von Dreele, 1994)] |
Rwp = 0.100 | 37 parameters |
Rexp = ? | 0 restraints |
χ2 = ? | 0 constraints |
2576 data points | (Δ/σ)max = 0.13 |
Crystal data top
NOP | β = 90.013 (6)° |
Mr = 60.98 | V = 420.27 (1) Å3 |
Monoclinic, I2/a | Z = 12 |
a = 8.5194 (2) Å | Neutron radiation, λ = ? Å |
b = 4.7448 (1) Å | T = 298 K |
c = 10.3970 (3) Å | cylinder, ? × ? × ? mm |
Data collection top
Polaris medium resolution diffractometer | Data collection mode: transmission |
Specimen mounting: silica tube | |
Refinement top
Rp = 0.110 | 2576 data points |
Rwp = 0.100 | 37 parameters |
Rexp = ? | 0 restraints |
χ2 = ? | (Δ/σ)max = 0.13 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
P1 | 0.25 | −0.010 (3) | 0.0 | 0.0127 (15)* | |
P2 | 0.0021 (9) | 0.2406 (6) | 0.1653 (4) | 0.0031 (7)* | |
O3 | −0.0112 (5) | 0.0597 (5) | 0.2912 (2) | 0.0126 (8)* | .5 |
N3 | −0.0112 (5) | 0.0597 (5) | 0.2912 (2) | 0.0126 (8)* | .5 |
O4 | 0.1572 (5) | 0.1811 (8) | 0.0963 (4) | 0.0323 (13)* | .5 |
N4 | 0.1572 (5) | 0.1811 (8) | 0.0963 (4) | 0.0323 (13)* | .5 |
O5 | −0.1362 (5) | 0.2106 (9) | 0.0701 (4) | 0.0335 (14)* | .5 |
N5 | −0.1362 (5) | 0.2106 (9) | 0.0701 (4) | 0.0335 (14)* | .5 |
Geometric parameters (Å, º) top
P1—O4 | 1.564 (10) | P2—O3 | 1.569 (4) |
P1—O4i | 1.564 (10) | P2—O3iv | 1.582 (3) |
P1—O5ii | 1.543 (10) | P2—O4 | 1.530 (7) |
P1—O5iii | 1.543 (10) | P2—O5 | 1.545 (6) |
| | | |
O5ii—P1—O5iii | 103.6 (10) | O3—P2—O4 | 110.7 (4) |
O5ii—P1—O4 | 110.0 (2) | O3iv—P2—O5 | 108.0 (3) |
O5ii—P1—O4i | 111.9 (2) | O3iv—P2—O4 | 105.6 (4) |
O5iii—P1—O4 | 111.9 (2) | O5—P2—O4 | 110.0 (2) |
O5iii—P1—O4i | 110.0 (2) | P2—O3—P2v | 139.3 (2) |
O4—P1—O4i | 109.3 (10) | P1ii—O5—P2 | 147.0 (5) |
O3—P2—O3iv | 106.7 (2) | P1—O4—P2 | 147.5 (5) |
O3—P2—O5 | 115.4 (4) | | |
Symmetry codes: (i) −x+1/2, y, −z; (ii) −x, −y, −z; (iii) x+1/2, −y, z; (iv) −x, y+1/2, −z+1/2; (v) −x, y−1/2, −z+1/2. |
Experimental details
Crystal data |
Chemical formula | NOP |
Mr | 60.98 |
Crystal system, space group | Monoclinic, I2/a |
Temperature (K) | 298 |
a, b, c (Å) | 8.5194 (2), 4.7448 (1), 10.3970 (3) |
β (°) | 90.013 (6) |
V (Å3) | 420.27 (1) |
Z | 12 |
Radiation type | Neutron, λ = ? Å |
µ (mm−1) | ? |
Specimen shape, size (mm) | Cylinder, ? × ? × ? |
|
Data collection |
Diffractometer | Polaris medium resolution diffractometer |
Specimen mounting | Silica tube |
Data collection mode | Transmission |
Scan method | ? |
2θ values (°) | 2θmin = ? 2θmax = ? 2θstep = ? |
|
Refinement |
R factors and goodness of fit | Rp = 0.110, Rwp = 0.100, Rexp = ?, χ2 = ? |
No. of data points | 2576 |
No. of parameters | 37 |
(Δ/σ)max | 0.13 |
Selected geometric parameters (Å, º) topP1—O4 | 1.564 (10) | P2—O3 | 1.569 (4) |
P1—O4i | 1.564 (10) | P2—O3iv | 1.582 (3) |
P1—O5ii | 1.543 (10) | P2—O4 | 1.530 (7) |
P1—O5iii | 1.543 (10) | P2—O5 | 1.545 (6) |
| | | |
O5ii—P1—O5iii | 103.6 (10) | O3—P2—O4 | 110.7 (4) |
O5ii—P1—O4 | 110.0 (2) | O3iv—P2—O5 | 108.0 (3) |
O5ii—P1—O4i | 111.9 (2) | O3iv—P2—O4 | 105.6 (4) |
O5iii—P1—O4 | 111.9 (2) | O5—P2—O4 | 110.0 (2) |
O5iii—P1—O4i | 110.0 (2) | P2—O3—P2v | 139.3 (2) |
O4—P1—O4i | 109.3 (10) | P1ii—O5—P2 | 147.0 (5) |
O3—P2—O3iv | 106.7 (2) | P1—O4—P2 | 147.5 (5) |
O3—P2—O5 | 115.4 (4) | | |
Symmetry codes: (i) −x+1/2, y, −z; (ii) −x, −y, −z; (iii) x+1/2, −y, z; (iv) −x, y+1/2, −z+1/2; (v) −x, y−1/2, −z+1/2. |