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In our earlier neutron diffraction study of the title compound at 30 K and 295 K an unconventional strategy in the refinement of hydrogen was applied and the same procedure has now been followed in the present investigation at 170 K and 90 K. There are two short O...H...O hydrogen bonds [2.437 (2) Å and 2.442 (2) Å at 30 K] and the `heavy-atom' structure is centrosymmetric (P\bar1) with centres of symmetry in the middle of the O...O bonds. However, statistical significance tests clearly show that an asymmetric location of both H atoms gives the most satisfactory description of the structure at all temperatures. The shift of hydrogen from the centre of symmetry is 0.15, 0.14, 0.15 and 0.15 Å for H2 at 30, 90, 170 and 295 K, respectively, and 0.15, 0.15, 0.15 and 0.12 Å for H4 (σ = 0.01 Å). Furthermore, the behaviour of H2 is very interesting: at 295 K and 170 K it is located on one side of the symmetry centre but at 90 K and 30 K it is located on the other side. A detailed determination of the unit-cell parameters by X-ray diffraction in the whole temperature range from 30 K to 295 K has revealed that the data points of the cell parameters as a function of temperature fall on two different straight lines with a sudden change in the slope around 135 K. It appears likely that the change in the location of H2 as the temperature is lowered is related to this behaviour. At 170 K, R(F) = 0.029 for 1236 reflections; at 90 K, R(F) = 0.030 for 1457 reflections.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768102004858/os0089sup1.cif
Contains datablocks text, 1, 2

sft

Structure factor file (SHELXL table format) https://doi.org/10.1107/S0108768102004858/os00891sup2.sft
Supplementary material

sft

Structure factor file (SHELXL table format) https://doi.org/10.1107/S0108768102004858/os00892sup3.sft
Supplementary material

CCDC references: 193575; 193576

Comment top

%T {βf (Comment section to be typeset from manuscript)}

Refinement top

neutron radiation, cell from X-ray data, weighting scheme: w = 1/[σ2(Fo2) + k2Fo4],k=0.06 at 170 K and at 90 K, parameters for atoms K1,Cl11,Cl21,O11, O21,O31,O41, C11,C21,C31,C41 constrained to P -1, see text

Computing details top

For both compounds, data collection: Aracor Diffractometer Control Program; cell refinement: STOE 4-circle X-ray Diffractometer Control Program; data reduction: ARACOR-DATRED vers. 950320; program(s) used to refine structure: UPALS Lundgren (1982).

Figures top
[Figure 1]
[Figure 2]
%T {βf (Figure captions to be typeset from manuscript)}
(1) top
Crystal data top
K2Cl4O8C8H2γ = 89.35 (5)°
Mr = 446.1V = 344.6 (3) Å3
Triclinic, P1Z = 1
Hall symbol: P 1Dx = 2.150 Mg m3
a = 5.048 (3) ÅNeutron radiation, λ = 1.207 Å
b = 7.840 (4) ŵ = 0.09 mm1
c = 8.839 (4) ÅT = 170 K
α = 81.46 (5)°Plate with 6 faces, colourless
β = 85.05 (5)°4.2 × 3.5 × 1.0 mm
Data collection top
Huber-Aracor 400 mm diameter four-circle
diffractometer
Rint = 0.036
θ–2θ scansθmax = 52°
Absorption correction: numerical
gaussian (Coppens, Leiserowitz & Rabinovich, 1965)
h = 06
Tmin = 0.700, Tmax = 0.917k = 1010
1614 measured reflectionsl = 1111
1370 independent reflections3 standard reflections every 33 reflections
1236 reflections with Fo2 > 3σ(Fo2) intensity decay: stable
Refinement top
Refinement on F2All H-atom parameters refined
R[F2 > 2σ(F2)] = 0.055(Δ/σ)max = 0.05
wR(F2) = 0.075Δρmax = 0.04 e Å3
S = 1.01Δρmin = 0.04 e Å3
1236 reflectionsExtinction correction: Lorentzian type I isotropic (Becker & Coppens, 1974, 1975)
119 parametersExtinction coefficient: 6580.1
Crystal data top
K2Cl4O8C8H2γ = 89.35 (5)°
Mr = 446.1V = 344.6 (3) Å3
Triclinic, P1Z = 1
a = 5.048 (3) ÅNeutron radiation, λ = 1.207 Å
b = 7.840 (4) ŵ = 0.09 mm1
c = 8.839 (4) ÅT = 170 K
α = 81.46 (5)°4.2 × 3.5 × 1.0 mm
β = 85.05 (5)°
Data collection top
Huber-Aracor 400 mm diameter four-circle
diffractometer
1236 reflections with Fo2 > 3σ(Fo2)
Absorption correction: numerical
gaussian (Coppens, Leiserowitz & Rabinovich, 1965)
Rint = 0.036
Tmin = 0.700, Tmax = 0.9173 standard reflections every 33 reflections
1614 measured reflections intensity decay: stable
1370 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.055119 parameters
wR(F2) = 0.075All H-atom parameters refined
S = 1.01Δρmax = 0.04 e Å3
1236 reflectionsΔρmin = 0.04 e Å3
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
K0.3011 (3)0.1556 (2)0.6239 (2)0.0159 (8)
Cl10.4700 (1)0.2461 (1)0.0585 (1)0.0152 (3)
Cl20.1324 (1)0.5711 (1)0.2016 (1)0.0188 (4)
O10.2357 (2)0.0033 (1)0.3337 (1)0.0173 (5)
O20.0261 (2)0.0490 (1)0.1226 (1)0.0148 (5)
O30.2501 (2)0.2209 (1)0.4020 (1)0.0159 (5)
O40.2980 (2)0.5061 (1)0.4144 (1)0.0157 (5)
C10.1506 (2)0.0507 (1)0.2213 (1)0.0103 (4)
C20.2011 (2)0.2330 (1)0.1886 (1)0.0096 (4)
C30.0552 (2)0.3717 (1)0.2514 (1)0.0105 (4)
C40.1824 (2)0.3610 (1)0.3652 (1)0.0106 (4)
H20.0250 (19)0.0074 (15)0.0042 (12)0.022 (2)
H40.494 (2)0.5036 (14)0.5163 (8)0.0201 (19)
K10.3011 (3)0.1556 (2)0.6239 (2)0.0159 (8)
Cl110.4700 (1)0.2461 (1)0.0585 (1)0.0152 (3)
Cl210.1324 (1)0.5711 (1)0.2016 (1)0.0188 (4)
O110.2357 (2)0.0033 (1)0.3337 (1)0.0173 (5)
O210.0261 (2)0.0490 (1)0.1226 (1)0.0148 (5)
O310.2501 (2)0.2209 (1)0.4020 (1)0.0159 (5)
O410.2980 (2)0.5061 (1)0.4144 (1)0.0157 (5)
C110.1506 (2)0.0507 (1)0.2213 (1)0.0103 (4)
C210.2011 (2)0.2330 (1)0.1886 (1)0.0096 (4)
C310.0552 (2)0.3717 (1)0.2514 (1)0.0105 (4)
C410.1824 (2)0.3610 (1)0.3652 (1)0.0106 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
K0.0176 (8)0.0115 (7)0.0185 (8)0.0017 (6)0.0023 (6)0.0037 (6)
Cl10.0121 (3)0.0170 (3)0.0166 (3)0.0005 (3)0.0061 (2)0.0023 (2)
Cl20.0204 (4)0.0097 (3)0.0263 (4)0.0007 (3)0.0104 (2)0.0066 (2)
O10.0182 (6)0.0163 (5)0.0174 (5)0.0006 (4)0.0064 (4)0.0076 (4)
O20.0205 (5)0.0102 (5)0.0137 (5)0.0036 (4)0.0035 (4)0.0025 (4)
O30.0164 (5)0.0104 (5)0.0209 (5)0.0008 (4)0.0073 (4)0.0047 (4)
O40.0138 (5)0.0109 (5)0.0225 (5)0.0018 (3)0.0089 (4)0.0039 (4)
C10.0104 (4)0.0089 (4)0.0115 (4)0.0003 (3)0.0006 (3)0.0027 (3)
C20.0086 (4)0.0086 (4)0.0115 (4)0.0001 (3)0.0012 (3)0.0021 (3)
C30.0100 (3)0.0080 (4)0.0134 (4)0.0001 (3)0.0033 (3)0.0022 (3)
C40.0094 (4)0.0088 (4)0.0136 (4)0.0001 (3)0.0031 (3)0.0024 (3)
H20.013 (3)0.0162 (19)0.0361 (17)0.0078 (19)0.0018 (19)0.0016 (13)
H40.0312 (16)0.0188 (14)0.010 (3)0.0024 (12)0.003 (2)0.001 (2)
K10.0176 (8)0.0115 (7)0.0185 (8)0.0017 (6)0.0023 (6)0.0037 (6)
Cl110.0121 (3)0.0170 (3)0.0166 (3)0.0005 (3)0.0061 (2)0.0023 (2)
Cl210.0204 (4)0.0097 (3)0.0263 (4)0.0007 (3)0.0104 (2)0.0066 (2)
O110.0182 (6)0.0163 (5)0.0174 (5)0.0006 (4)0.0064 (4)0.0076 (4)
O210.0205 (5)0.0102 (5)0.0137 (5)0.0036 (4)0.0035 (4)0.0025 (4)
O310.0164 (5)0.0104 (5)0.0209 (5)0.0008 (4)0.0073 (4)0.0047 (4)
O410.0138 (5)0.0109 (5)0.0225 (5)0.0018 (3)0.0089 (4)0.0039 (4)
C110.0104 (4)0.0089 (4)0.0115 (4)0.0003 (3)0.0006 (3)0.0027 (3)
C210.0086 (4)0.0086 (4)0.0115 (4)0.0001 (3)0.0012 (3)0.0021 (3)
C310.0100 (3)0.0080 (4)0.0134 (4)0.0001 (3)0.0033 (3)0.0022 (3)
C410.0094 (4)0.0088 (4)0.0136 (4)0.0001 (3)0.0031 (3)0.0024 (3)
Geometric parameters (Å, º) top
K—O12.710 (2)C1—C21.515 (1)
K—O41i2.723 (2)C2—C31.342 (1)
Cl1—C21.714 (1)C3—C41.508 (1)
Cl2—C31.718 (1)O2—H21.214 (11)
O1—C11.224 (1)O21—H21.243 (11)
O2—C11.283 (1)O4—H41.282 (10)
O3—C41.228 (1)O41ii—H41.175 (11)
O4—C41.283 (1)
O1—C1—O2123.4 (1)C2—C3—C4122.5 (1)
O1—C1—C2120.1 (1)C3—C4—O3119.7 (1)
O2—C1—C2116.4 (1)C3—C4—O4114.3 (1)
C1—C2—C3125.3 (1)O3—C4—O4125.9 (1)
C1—C2—Cl1112.5 (1)H2—O2—C1116.8 (5)
Cl1—C2—C3122.3 (1)H2—O21—C11117.7 (5)
C2—C3—Cl2120.4 (1)H4—O4—C4116.2 (5)
Cl2—C3—C4117.1 (1)H4iii—O41—C41114.9 (6)
Symmetry codes: (i) x, y1, z+1; (ii) x1, y1, z+1; (iii) x+1, y+1, z1.
(2) top
Crystal data top
K2Cl4O8C8H2γ = 89.16 (4)°
Mr = 446.1V = 342.6 (2) Å3
Triclinic, P1Z = 1
Hall symbol: P 1Dx = 2.162 Mg m3
a = 5.031 (3) ÅNeutron radiation, λ = 1.207 Å
b = 7.827 (4) ŵ = 0.09 mm1
c = 8.835 (5) ÅT = 90 K
α = 81.24 (4)°Plate with 6 faces, colourless
β = 85.17 (4)°4.2 × 3.5 × 1.0 mm
Data collection top
Huber-Aracor 400 mm diameter four-circle
diffractometer
Rint = 0.034
θ–2θ scansθmax = 52°
Absorption correction: numerical
gaussian (Coppens, Leiserowitz & Rabinovich, 1965)
h = 06
Tmin = 0.702, Tmax = 0.916k = 1010
1880 measured reflectionsl = 1111
1580 independent reflections3 standard reflections every 33 reflections
1457 reflections with Fo2 > 3σ(Fo2) intensity decay: stable
Refinement top
Refinement on F2All H-atom parameters refined
R[F2 > 2σ(F2)] = 0.054(Δ/σ)max = 0.05
wR(F2) = 0.080Δρmax = 0.04 e Å3
S = 1.09Δρmin = 0.04 e Å3
1457 reflectionsExtinction correction: Lorentzian type I isotropic (Becker & Coppens, 1974, 1975)
119 parametersExtinction coefficient: 7038.3
Crystal data top
K2Cl4O8C8H2γ = 89.16 (4)°
Mr = 446.1V = 342.6 (2) Å3
Triclinic, P1Z = 1
a = 5.031 (3) ÅNeutron radiation, λ = 1.207 Å
b = 7.827 (4) ŵ = 0.09 mm1
c = 8.835 (5) ÅT = 90 K
α = 81.24 (4)°4.2 × 3.5 × 1.0 mm
β = 85.17 (4)°
Data collection top
Huber-Aracor 400 mm diameter four-circle
diffractometer
1457 reflections with Fo2 > 3σ(Fo2)
Absorption correction: numerical
gaussian (Coppens, Leiserowitz & Rabinovich, 1965)
Rint = 0.034
Tmin = 0.702, Tmax = 0.9163 standard reflections every 33 reflections
1880 measured reflections intensity decay: stable
1580 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.054119 parameters
wR(F2) = 0.080All H-atom parameters refined
S = 1.09Δρmax = 0.04 e Å3
1457 reflectionsΔρmin = 0.04 e Å3
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
K0.3018 (3)0.1558 (2)0.6241 (2)0.0100 (6)
Cl10.4732 (1)0.2449 (1)0.0595 (1)0.0097 (3)
Cl20.1359 (1)0.5712 (1)0.2025 (1)0.0125 (3)
O10.2353 (2)0.0021 (1)0.3342 (1)0.0112 (4)
O20.0253 (2)0.0501 (1)0.1220 (1)0.0094 (4)
O30.2506 (2)0.2205 (1)0.4022 (1)0.0101 (4)
O40.2970 (2)0.5065 (1)0.4149 (1)0.0102 (4)
C10.1507 (1)0.0496 (1)0.2216 (1)0.0070 (3)
C20.2030 (1)0.2323 (1)0.1893 (1)0.0070 (3)
C30.0574 (1)0.3712 (1)0.2522 (1)0.0072 (3)
C40.1818 (1)0.3605 (1)0.3654 (1)0.0070 (3)
H20.0079 (18)0.0095 (11)0.0148 (8)0.0160 (11)
H40.5221 (16)0.4924 (11)0.5089 (9)0.0175 (11)
K10.3018 (3)0.1558 (2)0.6241 (2)0.0100 (6)
Cl110.4732 (1)0.2449 (1)0.0595 (1)0.0097 (3)
Cl210.1359 (1)0.5712 (1)0.2025 (1)0.0125 (3)
O110.2353 (2)0.0021 (1)0.3342 (1)0.0112 (4)
O210.0253 (2)0.0501 (1)0.1220 (1)0.0094 (4)
O310.2506 (2)0.2205 (1)0.4022 (1)0.0101 (4)
O410.2970 (2)0.5065 (1)0.4149 (1)0.0102 (4)
C110.1507 (1)0.0496 (1)0.2216 (1)0.0070 (3)
C210.2030 (1)0.2323 (1)0.1893 (1)0.0070 (3)
C310.0574 (1)0.3712 (1)0.2522 (1)0.0072 (3)
C410.1818 (1)0.3605 (1)0.3654 (1)0.0070 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
K0.0090 (6)0.0090 (6)0.0119 (6)0.0008 (5)0.0014 (4)0.0014 (5)
Cl10.0071 (3)0.0108 (3)0.0110 (3)0.0004 (2)0.0038 (2)0.0013 (2)
Cl20.0128 (3)0.0064 (2)0.0164 (3)0.0001 (2)0.0058 (2)0.0037 (2)
O10.0116 (4)0.0108 (4)0.0111 (4)0.0006 (3)0.0035 (3)0.0041 (3)
O20.0104 (4)0.0080 (4)0.0098 (4)0.0014 (3)0.0022 (3)0.0010 (3)
O30.0095 (4)0.0074 (4)0.0135 (4)0.0001 (3)0.0037 (3)0.0024 (3)
O40.0083 (4)0.0081 (4)0.0143 (4)0.0017 (3)0.0046 (3)0.0019 (3)
C10.0066 (3)0.0062 (3)0.0081 (3)0.0004 (3)0.0007 (2)0.0011 (3)
C20.0062 (3)0.0067 (3)0.0082 (3)0.0001 (3)0.0007 (3)0.0009 (3)
C30.0066 (3)0.0058 (3)0.0091 (3)0.0002 (3)0.0022 (2)0.0015 (3)
C40.0058 (3)0.0064 (3)0.0090 (3)0.0001 (3)0.0019 (3)0.0013 (3)
H20.0225 (12)0.0116 (10)0.0138 (12)0.0035 (9)0.0088 (9)0.0088 (9)
H40.0165 (12)0.0146 (10)0.0215 (12)0.0054 (9)0.0084 (9)0.0102 (9)
K10.0090 (6)0.0090 (6)0.0119 (6)0.0008 (5)0.0014 (4)0.0014 (5)
Cl110.0071 (3)0.0108 (3)0.0110 (3)0.0004 (2)0.0038 (2)0.0013 (2)
Cl210.0128 (3)0.0064 (2)0.0164 (3)0.0001 (2)0.0058 (2)0.0037 (2)
O110.0116 (4)0.0108 (4)0.0111 (4)0.0006 (3)0.0035 (3)0.0041 (3)
O210.0104 (4)0.0080 (4)0.0098 (4)0.0014 (3)0.0022 (3)0.0010 (3)
O310.0095 (4)0.0074 (4)0.0135 (4)0.0001 (3)0.0037 (3)0.0024 (3)
O410.0083 (4)0.0081 (4)0.0143 (4)0.0017 (3)0.0046 (3)0.0019 (3)
C110.0066 (3)0.0062 (3)0.0081 (3)0.0004 (3)0.0007 (2)0.0011 (3)
C210.0062 (3)0.0067 (3)0.0082 (3)0.0001 (3)0.0007 (3)0.0009 (3)
C310.0066 (3)0.0058 (3)0.0091 (3)0.0002 (3)0.0022 (2)0.0015 (3)
C410.0058 (3)0.0064 (3)0.0090 (3)0.0001 (3)0.0019 (3)0.0013 (3)
Geometric parameters (Å, º) top
K—O12.704 (2)C1—C21.515 (1)
K—O41i2.717 (2)C2—C31.341 (1)
Cl1—C21.715 (1)C3—C41.509 (1)
Cl2—C31.721 (1)O2—H21.320 (7)
O1—C11.224 (1)O21—H21.127 (8)
O2—C11.285 (1)O4—H41.358 (8)
O3—C41.226 (1)O41ii—H41.087 (8)
O4—C41.288 (1)
O1—C1—O2123.5 (1)C2—C3—C4122.5 (1)
O1—C1—C2120.2 (1)C3—C4—O3119.9 (1)
O2—C1—C2116.3 (1)C3—C4—O4114.2 (1)
C1—C2—C3125.2 (1)O3—C4—O4125.9 (1)
C1—C2—Cl1112.5 (1)H2—O2—C1121.9 (4)
Cl1—C2—C3122.4 (1)H2—O21—C11111.7 (4)
C2—C3—Cl2120.3 (1)H4—O4—C4113.2 (4)
Cl2—C3—C4117.2 (1)H4iii—O41—C41118.3 (5)
Symmetry codes: (i) x, y1, z+1; (ii) x1, y1, z+1; (iii) x+1, y+1, z1.

Experimental details

(1)(2)
Crystal data
Chemical formulaK2Cl4O8C8H2K2Cl4O8C8H2
Mr446.1446.1
Crystal system, space groupTriclinic, P1Triclinic, P1
Temperature (K)17090
a, b, c (Å)5.048 (3), 7.840 (4), 8.839 (4)5.031 (3), 7.827 (4), 8.835 (5)
α, β, γ (°)81.46 (5), 85.05 (5), 89.35 (5)81.24 (4), 85.17 (4), 89.16 (4)
V3)344.6 (3)342.6 (2)
Z11
Radiation typeNeutron, λ = 1.207 ÅNeutron, λ = 1.207 Å
µ (mm1)0.090.09
Crystal size (mm)4.2 × 3.5 × 1.04.2 × 3.5 × 1.0
Data collection
DiffractometerHuber-Aracor 400 mm diameter four-circle
diffractometer
Huber-Aracor 400 mm diameter four-circle
diffractometer
Absorption correctionNumerical
gaussian (Coppens, Leiserowitz & Rabinovich, 1965)
Numerical
gaussian (Coppens, Leiserowitz & Rabinovich, 1965)
Tmin, Tmax0.700, 0.9170.702, 0.916
No. of measured, independent and
observed [Fo2 > 3σ(Fo2)] reflections
1614, 1370, 1236 1880, 1580, 1457
Rint0.0360.034
(sin θ/λ)max1)0.6530.653
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.055, 0.075, 1.01 0.054, 0.080, 1.09
No. of reflections12361457
No. of parameters119119
No. of restraints??
H-atom treatmentAll H-atom parameters refinedAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.04, 0.040.04, 0.04

Computer programs: Aracor Diffractometer Control Program, STOE 4-circle X-ray Diffractometer Control Program, ARACOR-DATRED vers. 950320, UPALS Lundgren (1982).

Selected geometric parameters (Å, º) for (1) top
K—O12.710 (2)C1—C21.515 (1)
K—O41i2.723 (2)C2—C31.342 (1)
Cl1—C21.714 (1)C3—C41.508 (1)
Cl2—C31.718 (1)O2—H21.214 (11)
O1—C11.224 (1)O21—H21.243 (11)
O2—C11.283 (1)O4—H41.282 (10)
O3—C41.228 (1)O41ii—H41.175 (11)
O4—C41.283 (1)
O1—C1—O2123.4 (1)C2—C3—C4122.5 (1)
O1—C1—C2120.1 (1)C3—C4—O3119.7 (1)
O2—C1—C2116.4 (1)C3—C4—O4114.3 (1)
C1—C2—C3125.3 (1)O3—C4—O4125.9 (1)
C1—C2—Cl1112.5 (1)H2—O2—C1116.8 (5)
Cl1—C2—C3122.3 (1)H2—O21—C11117.7 (5)
C2—C3—Cl2120.4 (1)H4—O4—C4116.2 (5)
Cl2—C3—C4117.1 (1)H4iii—O41—C41114.9 (6)
Symmetry codes: (i) x, y1, z+1; (ii) x1, y1, z+1; (iii) x+1, y+1, z1.
Selected geometric parameters (Å, º) for (2) top
K—O12.704 (2)C1—C21.515 (1)
K—O41i2.717 (2)C2—C31.341 (1)
Cl1—C21.715 (1)C3—C41.509 (1)
Cl2—C31.721 (1)O2—H21.320 (7)
O1—C11.224 (1)O21—H21.127 (8)
O2—C11.285 (1)O4—H41.358 (8)
O3—C41.226 (1)O41ii—H41.087 (8)
O4—C41.288 (1)
O1—C1—O2123.5 (1)C2—C3—C4122.5 (1)
O1—C1—C2120.2 (1)C3—C4—O3119.9 (1)
O2—C1—C2116.3 (1)C3—C4—O4114.2 (1)
C1—C2—C3125.2 (1)O3—C4—O4125.9 (1)
C1—C2—Cl1112.5 (1)H2—O2—C1121.9 (4)
Cl1—C2—C3122.4 (1)H2—O21—C11111.7 (4)
C2—C3—Cl2120.3 (1)H4—O4—C4113.2 (4)
Cl2—C3—C4117.2 (1)H4iii—O41—C41118.3 (5)
Symmetry codes: (i) x, y1, z+1; (ii) x1, y1, z+1; (iii) x+1, y+1, z1.
 

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