The structure of meneghinite (CuPb13Sb7S24), from the Bottino mine in the Apuan Alps (Italy), has been solved and refined as an incommensurate structure in four-dimensional superspace. The structure is orthorhombic, superspace group Pnma(0β0)00s, cell parameters a = 24.0549 (3), b = 4.1291 (6), c = 11.3361 (16) Å, modulation vector q = 0.5433 (4)b*. The structure was refined from 6604 reflections to a final R = 0.0479. The model includes modulation of both atomic positions and displacement parameters, as well as occupational waves. The driving forces stabilizing the modulated structure of meneghinite are linked to the occupation modulation of Cu and some of the Pb atoms. As a consequence of the Cu/[] and Pb/Sb modulations, three- to sevenfold coordinations of the M cations (Pb/Sb) occur in different parts of the structure. The almost bimodal distribution of the occupation of Cu/[] and Pb/Sb at M5 conforms with the coupled substitution Sb3+ + [] → Pb2+ + Cu+, thus corroborating the hypothesis deduced previously for the incorporation of copper in the meneghinite structure. The very small departure (∼0.54 versus 0.50) from the commensurate value of the modulation raises the question of whether other sulfosalts considered superstructures have been properly described, and, in this light, if incommensurate modulation in sulfosalts could be much more common than thought.
Supporting information
B-IncStrDB reference: 13202EGzpbI
CCDC reference: 1533002
Crystal data top
Cu0.966Pb13.196S24Sb6.804 | V = 1126.0 (2) Å3 |
Mr = 4393.3 | Z = 1 |
Orthorhombic, Pnma(0β0)00s† | F(000) = 1839 |
q = 0.543300b* | Dx = 6.479 Mg m−3 |
a = 24.0549 (3) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 4.1291 (6) Å | µ = 54.69 mm−1 |
c = 11.3361 (16) Å | T = 297 K |
† Symmetry operations: (1) x1, x2, x3, x4; (2) −x1+1/2, −x2, x3+1/2, −x4+1/2; (3) −x1, x2+1/2, −x3, x4+1/2; (4) x1+1/2, −x2+1/2, −x3+1/2, −x4; (5) −x1, −x2, −x3, −x4; (6) x1+1/2, x2, −x3+1/2, x4+1/2; (7) x1, −x2+1/2, x3, −x4+1/2; (8) −x1+1/2, x2+1/2, x3+1/2, x4.
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Data collection top
Oxford Diffraction CCD diffractometer | 6604 independent reflections |
Radiation source: X-ray tube | 4696 reflections with I > 3σ(I) |
Graphite monochromator | |
Refinement top
Refinement on F2 | 216 parameters |
R[F2 > 2σ(F2)] = 0.048 | 0 restraints |
wR(F2) = 0.115 | 78 constraints |
S = 1.97 | Weighting scheme based on measured s.u.'s w = 1/(σ2(I) + 0.0004I2) |
6604 reflections | (Δ/σ)max = 0.807 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Cu1 | 0.247 (2) | 0.25 | −0.209 (5) | 0.0388 (11) | 0.239 (4) |
Pb1 | 0.125229 (14) | 0.25 | 0.15769 (3) | 0.02675 (11) | |
Pb2 | 0.064759 (19) | 0.75 | 0.46575 (4) | 0.02537 (16) | 0.4800 (17) |
Sb2 | 0.064759 (19) | 0.75 | 0.46575 (4) | 0.02537 (16) | 0.5199 (17) |
Pb3 | 0.025121 (19) | 0.25 | −0.15251 (4) | 0.02636 (16) | 0.5246 (18) |
Sb3 | 0.025121 (19) | 0.25 | −0.15251 (4) | 0.02636 (16) | 0.4754 (18) |
Pb4 | 0.215255 (15) | 0.25 | 0.48311 (4) | 0.03405 (13) | |
Pb5 | 0.15041 (2) | 0.75 | −0.21855 (5) | 0.02817 (16) | 0.2841 |
Sb5 | 0.15041 (2) | 0.75 | −0.21855 (5) | 0.02817 (16) | 0.7159 |
S1 | 0.15229 (8) | 0.75 | 0.33925 (19) | 0.0214 (6) | |
S2 | −0.06368 (9) | 0.25 | −0.02736 (18) | 0.0214 (6) | |
S3 | 0.23688 (9) | 0.75 | −0.3373 (2) | 0.0244 (6) | |
S4 | −0.02045 (9) | 0.75 | −0.28375 (19) | 0.0240 (6) | |
S5 | 0.10735 (9) | 0.25 | 0.5944 (2) | 0.0263 (6) | |
S6 | 0.18416 (9) | 0.25 | −0.0896 (2) | 0.0353 (7) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu1 | 0.0318 (17) | 0.0351 (18) | 0.050 (2) | 0 | −0.0051 (14) | 0 |
Pb1 | 0.02884 (19) | 0.02372 (18) | 0.0277 (2) | 0 | 0.00114 (13) | 0 |
Pb2 | 0.0275 (3) | 0.0243 (3) | 0.0244 (3) | 0 | 0.00051 (18) | 0 |
Sb2 | 0.0275 (3) | 0.0243 (3) | 0.0244 (3) | 0 | 0.00051 (18) | 0 |
Pb3 | 0.0291 (3) | 0.0243 (3) | 0.0257 (3) | 0 | 0.00392 (18) | 0 |
Sb3 | 0.0291 (3) | 0.0243 (3) | 0.0257 (3) | 0 | 0.00392 (18) | 0 |
Pb4 | 0.02498 (19) | 0.0333 (2) | 0.0439 (3) | 0 | 0.00206 (15) | 0 |
Pb5 | 0.0236 (3) | 0.0335 (3) | 0.0275 (3) | 0 | −0.0003 (2) | 0 |
Sb5 | 0.0236 (3) | 0.0335 (3) | 0.0275 (3) | 0 | −0.0003 (2) | 0 |
S1 | 0.0222 (10) | 0.0230 (10) | 0.0189 (10) | 0 | 0.0000 (8) | 0 |
S2 | 0.0240 (10) | 0.0214 (10) | 0.0188 (10) | 0 | 0.0008 (8) | 0 |
S3 | 0.0255 (10) | 0.0248 (10) | 0.0229 (11) | 0 | 0.0033 (8) | 0 |
S4 | 0.0252 (10) | 0.0260 (10) | 0.0207 (11) | 0 | −0.0007 (8) | 0 |
S5 | 0.0273 (10) | 0.0279 (11) | 0.0237 (11) | 0 | 0.0002 (8) | 0 |
S6 | 0.0259 (11) | 0.0552 (15) | 0.0247 (12) | 0 | −0.0001 (9) | 0 |
Bond lengths (Å) top | Average | Minimum | Maximum |
Cu1—Pb4i | 3.22 (9) | 3.14 (14) | 3.32 (14) |
Cu1—Pb4ii | 3.35 (8) | 3.10 (11) | 3.46 (11) |
Cu1—Pb4iii | 3.35 (8) | 3.10 (11) | 3.46 (11) |
Cu1—Pb5iv | 3.29 (8) | 3.16 (10) | 3.34 (10) |
Cu1—Pb5 | 3.29 (8) | 3.15 (10) | 3.34 (10) |
Cu1—S1iii | 2.41 (8) | 2.39 (13) | 2.45 (13) |
Cu1—S3iv | 2.36 (8) | 2.29 (9) | 2.52 (9) |
Cu1—S3 | 2.37 (8) | 2.29 (9) | 2.52 (9) |
Cu1—S6 | 2.42 (9) | 2.29 (13) | 2.48 (13) |
Pb1—S1iv | 2.988 (3) | 2.949 (4) | 3.042 (4) |
Pb1—S1 | 2.988 (3) | 2.949 (4) | 3.042 (4) |
Pb1—S2v | 2.939 (3) | 2.859 (4) | 2.987 (4) |
Pb1—S2vi | 2.939 (3) | 2.859 (4) | 2.987 (4) |
Pb1—S4v | 2.901 (4) | 2.891 (6) | 2.907 (6) |
Pb2—Pb2vii | 3.7609 (11) | 3.7302 (13) | 3.9507 (13) |
Pb2—Pb2viii | 3.7626 (11) | 3.7302 (13) | 3.9506 (13) |
Pb2—Sb2 | 0 | 0 | 0 |
Pb2—S1 | 2.587 (3) | 2.445 (6) | 2.673 (6) |
Pb2—S4v | 3.044 (4) | 2.890 (5) | 3.342 (5) |
Pb2—S4vi | 3.045 (4) | 2.890 (5) | 3.337 (5) |
Pb2—S5 | 2.802 (4) | 2.496 (4) | 2.983 (4) |
Pb2—S5ix | 2.803 (4) | 2.490 (4) | 2.983 (4) |
Sb2—S1 | 2.529 (3) | 2.411 (6) | 2.660 (6) |
Sb2—S5 | 2.684 (4) | 2.427 (4) | 2.982 (4) |
Sb2—S5ix | 2.686 (4) | 2.427 (4) | 2.983 (4) |
Pb3—Sb3 | 0 | 0 | 0 |
Pb3—Pb5iv | 3.6940 (11) | 3.6708 (13) | 3.7470 (13) |
Pb3—Pb5 | 3.6944 (11) | 3.6708 (13) | 3.7480 (13) |
Pb3—S2 | 2.597 (3) | 2.462 (6) | 2.680 (6) |
Pb3—S2v | 3.010 (3) | 2.936 (4) | 3.199 (4) |
Pb3—S2vi | 3.010 (3) | 2.936 (4) | 3.200 (4) |
Pb3—S4iv | 2.838 (4) | 2.517 (4) | 3.013 (4) |
Pb3—S4 | 2.838 (4) | 2.520 (4) | 3.013 (4) |
Sb3—S2 | 2.544 (3) | 2.438 (6) | 2.665 (6) |
Sb3—S4iv | 2.717 (4) | 2.452 (4) | 2.993 (4) |
Sb3—S4 | 2.717 (4) | 2.452 (4) | 2.994 (4) |
Pb4—S1iv | 3.037 (3) | 2.890 (4) | 3.137 (4) |
Pb4—S1 | 3.037 (3) | 2.890 (4) | 3.136 (4) |
Pb4—S3x | 2.948 (4) | 2.830 (4) | 3.076 (4) |
Pb4—S3xi | 2.947 (4) | 2.830 (4) | 3.076 (4) |
Pb4—S5 | 2.893 (4) | 2.843 (6) | 2.953 (6) |
Pb5—Sb5 | 0 | 0 | 0 |
Pb5—S3 | 2.519 (4) | 2.429 (6) | 2.596 (6) |
Pb5—S5i | 3.047 (4) | 2.894 (5) | 3.284 (5) |
Pb5—S5xii | 3.045 (4) | 2.894 (5) | 3.280 (5) |
Pb5—S6 | 2.781 (4) | 2.532 (5) | 2.996 (5) |
Pb5—S6ix | 2.780 (4) | 2.529 (5) | 2.996 (5) |
Sb5—S3 | 2.481 (4) | 2.419 (6) | 2.596 (6) |
Sb5—S6 | 2.658 (4) | 2.411 (5) | 2.996 (5) |
Sb5—S6ix | 2.658 (4) | 2.411 (5) | 2.996 (5) |
Symmetry codes: (i) x1, x2, x3−1, x4; (ii) −x1+1/2, −x2, x3−1/2, −x4+1/2; (iii) −x1+1/2, −x2+1, x3−1/2, −x4+1/2; (iv) x1, x2−1, x3, x4; (v) −x1, x2−1/2, −x3, x4+1/2; (vi) −x1, x2+1/2, −x3, x4+1/2; (vii) −x1, x2−1/2, −x3+1, x4+1/2; (viii) −x1, x2+1/2, −x3+1, x4+1/2; (ix) x1, x2+1, x3, x4; (x) x1, x2−1, x3+1, x4; (xi) x1, x2, x3+1, x4; (xii) x1, x2+1, x3−1, x4. |