Extension of the Pt III Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper marks a significant addition to the spectroscopic literature by analysing the higher-levels of Pt III, using a combination of theoretical calculations with the semi-relativistic Cowan code and with the fully relativistic GRASP92 code and fitting using orthogonal operator methods.   The author has immense experience and it shows.

I suspect line 28 of the text should read "... so out of reach of Pt III..."; other than that the English is impeccable.

Author Response

Thank you for positive review. The style and language were corrected due to invaluable suggestions by Reviewer #3

Reviewer 2 Report

Comments and Suggestions for Authors

This paper presents a new experimental study of the spectrum of Pt III. Knowledge of the latter is very useful for the astrophysical community because many Pt III lines have already been observed in the spectra of chemically particular stars. Additionally, spectroscopic data for heavy ions, such as Pt III, are currently in high demand for the analysis of kilonova spectra observed following neutron star mergers. All these motivations are well described in the introduction of the article.

There is no doubt that the work was meticulously carried out by this highly recognized specialist in experimental spectroscopy. The instrumental details as well as the observational approach are clearly described in the manuscript. New results in terms of wavelengths and energy levels are numerous and supported by the use of theoretical and semi-empirical methods based on well-established Hartree-Fock and Dirac-Fock approaches.

Given the number of original results obtained, their reliability, their interest for the scientific community and the clarity of the manuscript, my opinion is that this article deserves to be accepted for publication in its current form.

 

Author Response

Thank you for positive review. 

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents results of a combined experimental and theoretical study that significantly extends the knowledge of electronic structure and radiative transitions in doubly ionized platinum ion. Results of this study, in addition to extending fundamental atomic physics of very complex 5d-transition atoms and ions, have applications in astrophysics that are rightfully noted by the Author in the Introduction. The scientific methods used have been extensively tested by the Author in his multiple previous publications, and he is a worldwide recognized expert on these methods. The manuscript is written in good style and language requiring only minor corrections and is concise and clear. It is well within the scope of Atoms. All relevant prior research is adequately cited. Thus, the manuscript deserves publication in Atoms after a minor revision outlined below.

1) Lines 53-55: “many Pt III lines in the region above 1300 Å are not symmetric … and their errors of the wavelength measurements can be much higher than 0.005 Å.” - How much higher? Specify the upper limit and give estimated uncertainties for each line in the table. Otherwise, provide the input files for LOPT (as a supplementary online material) containing the adopted wavelength uncertainties.

2) Tables 1 and 2: Level designations produced by the old version of Uylings’s orthogonal operators code are hard to read and require much technical work to be converted to standard spectroscopic designations. Their format differs from that of Cowan’s codes used in Ref. [1], which makes it hard to relate the even levels to those of Ref. [1]. Peter Uylings has a newer version of his code that uses the currently standard Nielson-Koster indexes instead of seniority quantum numbers and omits the unnecessary indexes for non-repeating terms, making the output look rather similar to Cowan’s and much closer to standard designations. I do not insist that the Author redoes the calculations with the newer code version and remakes the tables, as I understand that it is difficult and may introduce new errors in addition to multiple mistakes already present in the tables (see below). It is just to inform the Author for future work.

3) There are multiple minor inconsistencies between Tables 1 and 2 and Ref. [1] in the level designations, energies, and J-values. These are marked and specified in the accompanying pdf file. They must be corrected in the revised version. After correcting these mistakes, the gA-values in the first column of Table 1 must be checked to make sure that they are extracted from correct transitions in the output of the orthogonal operators code.

4) Footnotes of Table 1:

·         The superscripted comment numbers are invisible - probably, because of a wrong left margin setting.

·         I do not see any footnotes denoting asymmetric lines. These were noted in Section 2 as having significantly larger wavelength uncertainties and thus should be marked in the Table. Either specify the measurement uncertainty for each line or state the common uncertainty of 0.005 A for symmetric lines and give different footnotes or coded comments in the Remark column for lines having different degrees of asymmetry (e.g., "sa", "ma", "va" for "slightly asymmetric", "medium asymmetric", "very asymmetric") and list estimated uncertainties for each of them, e.g., "sa - 0.010 A, ma - 0.015 A, va - 0.02 A".

·         In the last footnote, the Remark “OIII” is not used in the Table. Instead, the Remark column contains “O3”.

5) Table 2:

·         Italicize “E” and “N” in the column headers and “J” in the table body.

·         Specify uncertainties of experimental energies.

6) Table 3: For ζ_6p of 5d⁷7p (which should be ζ_7p), the Parameter Status in the last column is given as “f”, which is not explained in the footnotes. Should it be “0”? In the footnote d, the symbol used to denote ranges (r4–r6, C₁–C₃) is showing as blank.

7) Lines 127-128: “All level energies of the 5d⁷6s configuration were fixed [in] the optimization of the 5d⁷6p + 5d⁶6s6p levels.” – This is inconsistent with the preceding text: "most of the 5f⁷6s agree with [1]" (implying that some disagree); "Several level energies ... were corrected." In fact, Table 1 contains four levels of 5d⁷6s that are marked as corrected; their energies differ from Ref. [1] by up to 0.5 cm⁻¹. Change the text to explain how these levels were corrected. For better usability of the results, it would be preferable to reoptimize all the known levels on the basis of a complete set of observed lines from this and previous works (and include the input files for LOPT as a supplementary material).

8) The absence of a Conclusions section strikes the eye. It would be appropriate to summarize the current knowledge of Pt III: how many levels and lines are known and in what spectral regions these lines are, how many observed lines are still unidentified, what problems need to be solved. Specifying the unsolved problems is vital for atomic spectroscopy, as the current view of most scientists is that this field is done and does not need to be funded anymore.

In addition to the above, many minor corrections to language and style are suggested in the accompanying marked-up PDF file (visible in Adobe Reader).

In conclusion, a minor revision is needed before this manuscript is accepted for publication in Atoms.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The language is generally fine, although I suggested several tens minor corrections in the accompanying pdf file.

Author Response

The response is in attached file.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

 

This paper reports on the experimental and theoretical analysis of Pt III spectrum

The experimental part has been conducted by the author using the sliding spark technology.

Theoretical analysis has been conducted using Cowan and GRASP atomic structure codes as well as other highly specialized codes used in atomic spectroscopy.

 

This paper is an update on the authjors’s 1993 work and provide comprehensive analysis of the Pt III spectrum.

This is a good and publishable work.

My only concern is whether Atoms journal is the best place to report on it.

I would expect that a journal specializing in spectroscopy would be a better home for it.

Alternatively, given the large amount of data reported in this work, I would consider Atomic Data and Nuclear Data Tables journal.

Author Response

Thank you for positive review.