Single-Crystal Structure of HP-Sc₂TeO₆ Prepared by High-Pressure/High-Temperature Synthesis

Round 1

Reviewer 1 Report

Crystals Sc2TeO6
The authors report synthesis, crystal structure and high-temperature behaviour of HP-Sc2TeO6. The structure is characterized by several experimental and theoretical methods. The differences between the high-pressure and normal-pressure modifications are discussed. The article can be accepted for publication taking into account the following minor comments.
Line 163 – P2/c, c italics.
Line 207 – Likely the charge distribution has been calculated by the program CHARDI2015 that is described in the following unquoted article: CHARDI2015 - Charge distribution analysis of non-molecular structures, J. Appl. Cryst. (2016). 49, 317-321.

Author Response

Dear reviewer, dear editors,

thank you very much for your quick and positive review. We are very happy about the comments. All comments were taken into account and the manuscript was changed accordingly. 
Line 163: spacegroup symbol, corrected!
Line 207: reference was added!

Best regards,
Gunter Heymann

Reviewer 2 Report

The submitted manuscript presents the synthesis and single-crystal structure of new high-pressure scandium tellurate  HP-Sc₂TeO₆. It was shown that HP modification adopts the Yb₂WO_6-type structure, while normal pressure Sc₂TeO₆ modification belongs to the Na₂SiF₆-type structure. The authors performed crystal-chemical analysis and suggested a reconstructive transformation of NP-Sc₂TeO₆ (sp.gr. P321) into HP-Sc₂TeO₆ (sp.gr. P2/c). High-temperature XRPD investigations confirmed the inverse transformation of the metastable HP-modification into the thermodynamically stable NP one at ambient conditions.

The results are an excellent contribution to the crystal chemistry of tellurate compounds.  The article is well structured. The results obtained are clearly described. The subject and object are fully consistent with the aims and scopes of the journal. Thus, I recommend accepting this paper for publication as presented.

Author Response

Dear reviewer, dear editors,

thank you very much for the fast review reports of our manuskript. We would also thank the reviewer for its excellent review.

Best regards,

Gunter Heymann