The Dynamic State of a Pseudo-Crystalline Structure of B42 Molecules
Round 1
Reviewer 1 Report
The science is good and interesting, but the English needs to be improved throughout the text. In addition, the authors need to cite some additional work published in journals and books, including those on Boron Science (https://www.routledge.com/Boron-Science-New-Technologies-and-Applications/Hosmane/p/book/9781439826621; https://www.worldscientific.com/worldscibooks/10.1142/q0130). After appropriate revision, this work will be suitable for publication in "Crystals" without further revision!
Author Response
Thanks for the positive comment about the manuscript. We took into account all your comments and made a performance revision. The English has been improved using MDPI English editing. Featured books have been cited.
Reviewer 2 Report
This manusript presents a mathematical model for the angular dynamics of B_42 molecular disks stacked in a column. I am no expert in the field of boron-based materials but I do not see what this work really adds to crystalline material research. In addition, this manuscript is not easy to read. My opinion is that this manuscript would be more suitable for a journal specialized in mechanics, where the readers might show more appreciation to the mathematical model.
Author Response
Thank you for discussing our work and comments. Regarding your remark about the difficulty of reading our manuscript, we improved the quality of the text in all the work using MDPI English editing and partially changed the introduction. In addition, we want to note the importance of theoretical research and mathematical models in the issues discussed in the article. Such studies stimulate progress in this area, help direct experimental work in a promising direction, and accelerate the synthesis of new materials. Molecular crystals, such as plastic fullerite, have the ability to accumulate energy on internal, rotational degrees of freedom. The same property is possessed by columns from B42 disks. Molecular crystals created from such columns must have outstanding hardness characteristics, since each molecule of such crystals is an elementary gyroscope and counteracts the effect on it. To understand this theoretical question, you need to have a rigorous mathematical model. We managed to create it on the basis of already established approaches and methods of classical mechanics. Therefore, there is no contribution to the mechanics themselves. However, an application of the methods of mechanics to the description of the rotational dynamics of molecules in molecular crystals has been performed. In relation to structures from B42, the character of angular displacements was found and the frequency characteristics of molecules were determined. We believe that a fairly rigorous mathematical model of the physical process can be very useful in the theoretical and practical construction of new materials based on molecular crystals.
Reviewer 3 Report
Here are some suggestions for improving the manuscript:
Abstract:
arising from the approach of B42molecules has been developed --> arising from B42molecules has been developed
- Introduction:
The authors [1] performed --> Pham et al. [1] performed
In this paper, we investigated the structure --> In this paper, we investigate the structure
each individual flat disk B42. --> each individual flat disk of B42.
the authors [16] showed --> Eshkalak et al. [16] showed
The acronym for density functional theory should be mentioned the first time it appears in the Introduction and not after that.
The way references are mentioned needs to be changed. For example, “[18] showed the…” should be changed to “Reference [18] showed the…”.
The introduction is not well written. There is a lot on BN, while the paper is about B42. Hence, I suggest shortening discussion on BN and introducing more discussion on B and its various forms. Additionally, it will be useful to convert the introduction into a number of paragraphs.
- Materials and Methods
The mesh structures of boron molecules are based on triangles Figure 1, as well as five, six and heptagons. --> The mesh structures of boron molecules are based on triangles in Figure 1, as well as pentagons, hexagons, and heptagons.
Author Response
Thank you for reading our manuscript and comments. Your comments helped us improve the article. We took into account all the comments and made appropriate improvements. All the above remarks regarding the English language were corrected, in addition, we used the services of MDPI English editing to improve the quality of the all text. In the introduction, there was a lot of work on boron nitride, this is due to the fact that the subject of our study is a material consisting of 2D B42 molecules, and BN is the most popular 2D material after graphene and consists of boron. And indeed, this was not a very good introduction for this article. We made a more general introduction - cited several books and chapters on boron, devoted part of the review to the properties of boron and its application in various fields, and added works on other studies of boron.
Round 2
Reviewer 2 Report
The manuscript has been revised and it reads better now. However, the major problem with this work persists, namely, that it seems to add very little to crystalline material research. In fact, this work is purely theoretical and has no clear connection to experiments.
I am still of the opinion that this manuscript is more suitable for publication in a journal specialized in mechanics. However, if the authors want their manuscript to be considered for publication in Crystals, they should at least explain how their theory can be qualitatively tested in experiments.
Author Response
How can a theory be tested in an experiment?
In the experiments, one can fix the period of angular vibrations of the B42 plates. Similar experiments were performed, for example, by Johnson et al. C60 Rotation in the Solid State: Dynamics of a Faceted Spherical Top. Science 1992, 255, 1235–1238, in the case of rotation of fullerenes in the plastic phase of fullerite using nuclear magnetic resonance. For this case, our research by Bubenchikov et al. Md-Simulation of Fullerene Rotations in Molecular Crystal Fullerite, Crystals 2019, 9 (10), 496 confirmed the qualitative nature of the angular displacements of fullerenes, which consists in the angular vibrations of C60 and subsequent reorientations of fullerenes. In addition, we obtained a quantitative agreement of the data both on the average frequency and on the time of reorientation of fullerenes. In the case of columns from B42, our calculated data may be a guideline for measurements. At the same time, data from independent experiments can be used to re-test the mathematical model. In addition, in experiments it is possible to determine the average distance between the B42 plates in columns and compare it with the results of calculations by the atom-atom model of plate interaction.
Reviewer 3 Report
Unfortunately, I think the Introduction still needs some work. The whole Introduction is one paragraph – it needs to be split into multiple paragraphs to improve readability. The paragraph needs to be changed when a new idea or point begins. For example, B and its allotropes could be one paragraph, BN could be another one, and so on. At the moment, it seems to me that different ideas and different materials are described randomly in the Introduction. Additionally, the Introduction has no flow, for instance, in line 29, there is a switch in the discussion from B30, B36, etc. to 2D materials or graphene analogs. I had to put an effort to understand why there is a switch.
Even though there is a similarity between B42 and BN, I don’t think the Introduction should be dominated by BN. The way the Introduction is written, it seems the paper is about BN and other materials.
The way references are referred to should be changed. For example, “In [33], …” should be written as “In reference [33], …” or “In ref [33], …”.
Author Response
We made improvements to the introduction, splitting it into paragraphs, grouping general information about boron, the subject of this study and the general properties of 2D materials, studies of 2D materials and other features associated with boron. The discussion of 2D materials has been shortened. Reduced the number of works devoted to BN (now only 4 works). We also tried to make the switching in the introduction more clear and consistent. The way references has been changed as recommended.
Round 3
Reviewer 2 Report
The authors should explain in the manuscript (preferably in the Discussion section) how their theory can be qualitatively tested in experiments. I thought I made it clear in my previous report. Until this is done I can not recommend this manuscript for publication in Crystals.
Author Response
The discussion section has been revised and improved in accordance with the recommendations. Some methods of verifying our theory were added to the discussion, as well as the connection between theory and experiment.
