The High Pressure Behavior of Galenobismutite, PbBi2S4: A Synchrotron Single Crystal X-ray Diffraction Study
, Tonci Balić-Žunić 2, Michael Hanfland 3 and Ines Collings 3Round 1
Reviewer 1 Report
This seems like a nice paper that reports the high pressure single crystal diffraction results on galenobismutite. The authors do a good job discussing previous work that’s been done. They report the crystal structure including lattice parameters, atomic positions, and also report an analysis on the evolution of polyhedral. I only have a few minor comments I’m curious about. The authors do not report any theoretical results, I’m wondering if there are any theoretical results or why the authors don’t discuss them? For the sake of reproducibility I’m wondering if the authors should report the spots for the SCXRD in the supplement, just showing lattice parameters instead of raw data seems a bit lacking. Page 2 line 61 there seems to be a typo, it says [1]s where [1] is a reference. The authors said Bi and Pb are difficult to distinguish in xrd, but I don’t think the authors reported how they dealt with this issue. I recommend this paper for publication in it’s present form, my questions are merely for my own curiosity.
Author Response
Response to Reviewer 1 Comments
Point 1: This seems like a nice paper that reports the high pressure single crystal diffraction results on galenobismutite. The authors do a good job discussing previous work that’s been done. They report the crystal structure including lattice parameters, atomic positions, and also report an analysis on the evolution of polyhedral. I only have a few minor comments I’m curious about. The authors do not report any theoretical results, I’m wondering if there are any theoretical results or why the authors don’t discuss them? For the sake of reproducibility I’m wondering if the authors should report the spots for the SCXRD in the supplement, just showing lattice parameters instead of raw data seems a bit lacking. Page 2 line 61 there seems to be a typo, it says [1]s where [1] is a reference. The authors said Bi and Pb are difficult to distinguish in xrd, but I don’t think the authors reported how they dealt with this issue. I recommend this paper for publication in it’s present form, my questions are merely for my own curiosity.
Response 1: Thank you to the referee for the nice words and comments to our paper.
Really there are very few theoretical data on sulphosalts, but now to follow his suggestion we introduce one paper by Olsen et al. 2010 about theoretical calculation on the effect of pressure on stereochemical activity of Bismuth and the comparison with experimental data.
We correct the mistakes in line 61.
We think that the .cif files we add as supplementary materials, allow to everyone to reproduce all data about lattice parameters and structural refinements. The lattice parameters were calculated by CrysAlis software not examining the diffraction spots, as occur for example with electron diffraction.
The distinction between Bi and Pb is described in detail in another paper by Pinto et al. 2005, who used bond lengths, bond valences and geometrical characteristics of the coordination polyhedral to interprete the occupancy on M1, M2 and M3 position. We add a sentence in the text to clarify this aspect.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This is an extremely good paper. The authors report very accurate studies which highlight the relevance of HP single crystal XRD. All the reported results are accurate and the conclusions are sound and supported by the experimental evidence. I have only minor comment regarding the style of the manuscript.
1. In the introduction the authors should highlight with a paragraph the relevance of HP single crystal XRD and the advantages again HP powder XRD including references to recent relevant works. For instance: D. Comboni et al Microporous and Mesoporous Materials 274 (2019) 171-175, Guennou, M., et al Phys. Rev. Lett. 112, 075501 ( 2014), J. Ruiz Fuertes et al Phys. Rev. B 95, 174105 (2017), and J. Ruiz Fuertes et al Phys. Rev. B 91, 104109 (2015).
2. The format of the figures changes very much from one to another. In same cases pressure is level as pressure in other as P and in others as Pressure. Please unify it. In some figures the label of the axes is larger than the units of the scale and in other is of the same size. I suggest to unify it too using a larger font for the label.
3. In Fig. 1 the names of the axis (x, y) are too small.
4. In Fig. 3 the numbers in the scales are too small. Maybe you can use less major ticks and more minor ticks increasing the size of the font.
5. The resolution of Fig. 5 appears to be low.
After these changes I recommend the acceptance of the article.
Author Response
This is an extremely good paper. The authors report very accurate studies which highlight the relevance of HP single crystal XRD. All the reported results are accurate and the conclusions are sound and supported by the experimental evidence. I have only minor comment regarding the style of the manuscript.
1. In the introduction the authors should highlight with a paragraph the relevance of HP single crystal XRD and the advantages again HP powder XRD including references to recent relevant works. For instance: D. Comboni et al Microporous and Mesoporous Materials 274 (2019) 171-175, Guennou, M., et al Phys. Rev. Lett. 112, 075501 ( 2014), J. Ruiz Fuertes et al Phys. Rev. B 95, 174105 (2017), and J. Ruiz Fuertes et al Phys. Rev. B 91, 104109 (2015).
We add a couple of the references suggested
2. The format of the figures changes very much from one to another. In same cases pressure is level as pressure in other as P and in others as Pressure. Please unify it. In some figures the label of the axes is larger than the units of the scale and in other is of the same size. I suggest to unify it too using a larger font for the label.
We uniform the format of figures and tables. Thank to referees to check all these mistakes
3. In Fig. 1 the names of the axis (x, y) are too small.
We skipped the names of the axis from the figure and we ister them on the figure caption
4. In Fig. 3 the numbers in the scales are too small. Maybe you can use less major ticks and more minor ticks increasing the size of the font.
We changed the figures
5. The resolution of Fig. 5 appears to be low.
We increase the resolution of this figure
After these changes I recommend the acceptance of the article.
Thank very much to the referee
Author Response File: Author Response.docx
Reviewer 3 Report
The paper reports a single-crystal X-ray diffraction study of PbBi2S4 at room temperature and high pressures. The crystal structure of this compound, galenobismutite, has been determined up to 21 GPa. The paper is clearly written and the experimental work is technically sounded.
The scientific contribution is however limited. The authors previously published a high-pressure study on this mineral in literature, up to 9 GPa using also single-crystal X-ray diffraction, which reported results on its compressibility and anisotropy. No phase transition has been found up to 21 GPa., Therefore, despite the fact that the present work has significantly extended the studied pressure range, new data only gives insight into the evolution of the compressibility parameters and small atomic displacements above that pressure.
Hereafter I detail some major critics:
1. In the introduction, line 63, it is stated that the atomic configuration of galenobismutite is close-packed, which is not the case.
2. Regarding the experimental details: Is the sample natural or was synthesized in a laboratory? The exact chemical composition of the sample should be provided (EDX analyses, for example).
3. Please, include in the ‘experimental details’ section the DAC optical aperture, the reciprocal space completeness and resolution.
4. Details of the data refinement at 20.9 GPa is missing in Table 1.
5. Figure 4 shows the bulk moduli and first-pressure derivatives of several sulfides of elements with lone electron pairs (LEP). However, the stoichiometry of these compounds is very different, and makes difficult to find systematics. I strongly reccomend to extent the discussion and compare the compressibility parameters of galenobismutite with those of other AB2S4 sulfides (with and without LEP) to get insight into (i) the role of cation sizes, (ii) the different electronegativities, and (iii) the role played by LEPs.
6. Lines 195-196. Please, change KPbBi2S4 by KPbBi2S4.
This manuscript could be published in Crystal once these major concerns are addressed.
Author Response
Response to Reviewer 3 Comments
The paper reports a single-crystal X-ray diffraction study of PbBi2S4 at room temperature and high pressures. The crystal structure of this compound, galenobismutite, has been determined up to 21 GPa. The paper is clearly written and the experimental work is technically sounded.
The scientific contribution is however limited. The authors previously published a high-pressure study on this mineral in literature, up to 9 GPa using also single-crystal X-ray diffraction, which reported results on its compressibility and anisotropy. No phase transition has been found up to 21 GPa., Therefore, despite the fact that the present work has significantly extended the studied pressure range, new data only gives insight into the evolution of the compressibility parameters and small atomic displacements above that pressure. Hereafter I detail some major critics:
1. In the introduction, line 63, it is stated that the atomic configuration of galenobismutite is close-packed, which is not the case.
2.
We change this sentence
3. Regarding the experimental details: Is the sample natural or was synthesized in a laboratory? The exact chemical composition of the sample should be provided (EDX analyses, for example).
We added the data on the sample
4. Please, include in the ‘experimental details’ section the DAC optical aperture, the reciprocal space completeness and resolution.
We added the requested information
5. Details of the data refinement at 20.9 GPa is missing in Table 1
We changed the table, sorry for the mistake.
6. Figure 4 shows the bulk moduli and first-pressure derivatives of several sulfides of elements with lone electron pairs (LEP). However, the stoichiometry of these compounds is very different, and makes difficult to find systematics. I strongly reccomend to extent the discussion and compare the compressibility parameters of galenobismutite with those of other AB2S4 sulfides (with and without LEP) to get insight into (i) the role of cation sizes, (ii) the different electronegativities, and (iii) the role played by LEPs.
We didn’t change figure 4 because this is only a preliminary analysis of the data. We think that the analysis of the chemical and electronic configuration of different cation on the compressibility and the structural evolution of all AB2S4 sulfides is quite complex. We are collecting several other compressibility and HP structural data data on sulphosalts, and we will organize a review paper on these aspects: which is the role of LEP, the role of cation size, the electronegativities and so on.
6. Lines 195-196. Please, change KPbBi2S4 by KPbBi2S4.
We corrected this mistake
This manuscript could be published in Crystal once these major concerns are addressed.
Think very much for his constructive suggestions
Round 2
Reviewer 3 Report
The authors of the manuscript have addressed my concerns regarding the experimental details and have corrected some minor typos. Data, from the crystallographic point of view, looks fine.
However, as I expressed in my previous report, “The scientific contribution is quite limited. The authors previously published a high-pressure study on this mineral, up to 9 GPa using also single-crystal X-ray diffraction, which reported results on its compressibility and anisotropy. No phase transition has been found up to 21 GPa., Therefore, despite the fact that the present work has significantly extended the studied pressure range, new data only gives insight into the evolution of the compressibility parameters and small atomic displacements above that pressure.” I strongly suggested the authors to extent the discussion and compare the compressibility behavior of galenobismutite with that of other AB2S4 sulfides (so the manuscript were more substantial, with the possibility of finding systematics and maybe physical insight into the role of lone electron pairs), but this recommendation has not been taken into account.
Author Response
We have checked the ICSD for the structural investigations of AB2S4 sulphides at high pressures. We could find only two articles that might report bulk moduli of such compounds:
Alvaro et al. High-pressure behavior of thiospinel Cu Cr2 S4. American Mineralogist (2014) 99, (5-6) p908-p913
Wittlinger, J.; Werner, S.; Schulz, H. On the amorphisation of Zn Cr2 S4 spinel under high pressure: X-ray diffraction studies Physics and Chemistry of Minerals (1997) 24, (*) p597-p600
It is not excluded that somebody made just compressibility measurement on this type of compounds and that is not reported in the ICSD, but wedoubt. Sulfides of this stoichiometry would be just thospinels, I believe, and we do not see a point to compare the compressibility data of galenobismutite to completely different structural type. I think that there are more structural connections between galenobismutite and other sulfosalts, than connections to some other compounds with matching formula type but completely different type of structure.
Round 3
Reviewer 3 Report
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