Abstract Obtaining meteoroid mass from head echo radar cross section depends on the assumed plasma density distribution around the meteoroid. An analytical model presented in Dimant and Oppenheim (2017a,https://doi.org/10.1002/2017JA023960; 2017b,https://doi.org/10.1002/2017JA023963) and simulation results presented in Sugar et al. (2018,https://doi.org/10.1002/2018JA025265) suggest the plasma density distribution is significantly different than the spherically symmetric Gaussian distribution used to calculate meteoroid masses in many previous studies. However, these analytical and simulation results ignored the effects of electric and magnetic fields and assumed quasi‐neutrality. This paper presents results from the first particle‐in‐cell simulations of head echo plasma that include electric and magnetic fields. The simulations show that the fields change the ion density distribution by less than ∼2% in the meteor head echo region, but the electron density distribution changes by up to tens of percent depending on the location, electron energies, and magnetic field orientation with respect to the meteoroid path.
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Reply to the Comment on “Realization of Lewis Basic Sodium Anion in the NaBH 3 − Cluster”
Abstract We reply to the comment by S. Pan and G. Frenking who challenged our interpretation of the Na−:→BH3dative bond in the recently synthesized NaBH3−cluster. Our conclusion remains the same as that in our original paper (https://doi.org/10.1002/anie.201907089andhttps://doi.org/10.1002/ange.201907089). This conclusion is additionally supported by the energetic pathways and NBO charges calculated at UCCSD and CASMP2(4,4) levels of theory. We also discussed the suitability of the Laplacian of electron density (QTAIM) and Adaptive Natural Density Partitioning (AdNDP) method for bond type assignment. It seems that AdNDP yields more sensible results. This discussion reveals that the complex realm of bonding is full of semantic inconsistencies, and we invite experimentalists and theoreticians to elaborate this topic and find solutions incorporating different views on the dative bond.
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- Award ID(s):
- 1664379
- PAR ID:
- 10147259
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 23
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 8760-8764
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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