Controlling Achiral and Chiral Properties with an Electric Field: A Next-Generation QTAIM Interpretation
, Steven R. Kirk 1,* and Samantha Jenkins 1,*
Round 1
Reviewer 1 Report
The manuscript by S. Kirk, S. Jenkins et al. describes the results of a computational study devoted to tuning of chiral properties with an electric field in the context next generation quantum theory of atoms in molecules (NG-QTAIM). The study itself constitutes development of NG-QTAIM and should be published in Symmetry. However, the Authors may consider the following remarks (mainly technical):
1) lines 124-126 and Supporting Materials: In many works describing “classical” QTAIM, there is a condition that l1<l2<l3 given but in the current work this condition is missing. Of course l1<l2, so ellipticity formula can be written without modulus symbols. Moreover, the Authors write about “e>0”. Ellipticity can be either greater or equal to zero, so the condition should be rather written as “ellipticity is not equal to zero” instead of being “greater than zero”.
2) line 114 and many others: In my opinion cross product symbol “x” should not be used instead of dot in multiplication (all values of electric field).
3) lines 251 and 252: Values are given without their units.
4) Figures in Supplementary Materials: Captions in Figures are sometimes a bit illegible.
5) Supplementary Materials file should be rather in a pdf format to avoid future problems with formatting.
Author Response
Reviewer 1: The manuscript by S. Kirk, S. Jenkins et al. describes the results of a computational study devoted to tuning of chiral properties with an electric field in the context next generation quantum theory of atoms in molecules (NG-QTAIM). The study itself constitutes development of NG-QTAIM and should be published in Symmetry. However, the Authors may consider the following remarks (mainly technical):
We thank the busy reviewer for the careful consideration of our manuscript.
1) lines 124-126 and Supporting Materials: In many works describing “classical” QTAIM, there is a condition that l1<l2<l3 given but in the current work this condition is missing. Of course l1<l2, so ellipticity formula can be written without modulus symbols.
The following corrected ellipticity ε = λ1/λ2 – 1 text has been added:
“Note, λ1 and λ2 both possess negative signs where λ1 ≤ λ2 < λ3 and λ3 > 0.”
Moreover, the Authors write about “e>0”. Ellipticity can be either greater or equal to zero, so the condition should be rather written as “ellipticity is not equal to zero” instead of being “greater than zero”.
The following text:
“For values of the ellipticity ε > 0”,
Has been replaced by the following text:
“For values of the ellipticity ε > 0 and where the ellipticity ε ≠ 0,”
2) line 114 and many others: In my opinion cross product symbol “x” should not be used instead of dot in multiplication (all values of electric field).
We can’t use the symbol “x” in our work as that also used to denote a vector product. For improved readability however, we have replace the Times New Roman 12 font dots with Times New Roman 14 font dots.
3) lines 251 and 252: Values are given without their units.
All instances of missing units have been corrected.
4) Figures in Supplementary Materials: Captions in Figures are sometimes a bit illegible.
We have clarified the figures in the Supplementary Materials.
5) Supplementary Materials file should be rather in a pdf format to avoid future problems with formatting.
We have provided the Supplementary Materials in .pdf format.
Reviewer 2 Report
1) Explain symbols Sa and Ra at line 67.
2) Non-numbered equations at lines 148, 149, 151
3) The consequence of reversed electric fields in various datasets might be described by their skewness.
Author Response
Reviewer 2:
1) Explain symbols Sa and Ra at line 67.
The original text:
“Previously [2] we established the stress tensor trajectory Tσ(s) classifications of Sa and Ra based on the clockwise (CW) vs. counterclockwise (CCW) torsions for Tσ(s) for lactic acid and alanine where distinct helical-shaped Tσ(s) are present.”
Has been replaced by the clarified text:
“Previously [2] we established the presence of distinct helical-shaped stress tensor trajectory Tσ(s) for lactic acid and alanine.”
2) Non-numbered equations at lines 148, 149, 151
Numbering of the expressions is now provided and referred to:
Cσ = [(e1σ∙dr)max]CCW - [(e1σ∙dr)max]CW (3)
The bond-flexing Fσ, defined as:
Fσ = [(e2σ∙dr)max]CCW - [(e2σ∙dr)max]CW (4)
The bond-flexing Fσ, see equation (4), provides a measure of the ‘flexing-strain’ of a bond-path for each dihedral angle which is particularly of use when a molecule is subjected to an E-field.
The bond-axiality Aσ for each dihedral angle provides a measure of the chiral asymmetry, is defined as:
Aσ = [(e3σ∙dr)max]CCW - [(e3σ∙dr)max]CW (5)
The bond-axiality Aσ, see equation (5), quantifies the direction of axial displacement of the bond critical point (BCP) in response to the bond-torsion (CCW vs. CW), i.e. the sliding of the BCP along the bond-path [22]. The (±) sign of the chirality Cσ, see equation (3)
3) The consequence of reversed electric fields in various datasets might be described by their skewness.
The results are in line with expectations of the known result that the direction of application of an E-field along a bond, parallel or anti-parallel, will has significantly different effects on the directional properties derived from electronic charge density distributions. We found this in our earlier investigations “Control of Chirality, Bond flexing and Anharmonicity in an Electric Field", Int. J. Quant. Chem. 112(22) e26793 (2021).
DOI: https://doi.org/10.1002/qua.26793
Reviewer 3 Report
The manuscript deals with the investigation of the chirality of alanine when exposed to a nonstructurally distorting electric-field. Authors applied the next generation QTAIM (NG-QTAIM) method, including the procedure to generate the stress tensor trajectories Tσ(s).Results are clearly presented in tables and graphs.
The NG-QTAIM method can be applied as a powerful analytical
method and cam open up a wide scientific field for "chiralism" of solid states and molecular systems. This makes this well written manuscript more valuable.
Author Response
Reviewer 3. The manuscript deals with the investigation of the chirality of alanine when exposed to a nonstructurally distorting electric-field. Authors applied the next generation QTAIM (NG-QTAIM) method, including the procedure to generate the stress tensor trajectories Tσ(s).Results are clearly presented in tables and graphs.
The NG-QTAIM method can be applied as a powerful analytical
method and cam open up a wide scientific field for "chiralism" of solid states and molecular systems. This makes this well written manuscript more valuable.
We thank the reviewer for their very positive and encouraging statements.
