# Colleen LavinNikon Instruments · NII

Colleen Lavin

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87

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## Publications

Publications (87)

Theoretical absorption oscillator strengths and wavelengths for rotational transitions of the C ² Π( v ′ = 0)- X ² Π( v ″) bands with v ″ = 0–6 of nitric oxide are reported. The Molecular Quantum Defect Orbital method has been used in the calculations and the known interaction between the C ² Π( v = 0) Rydberg and the B ² Π ( v = 7) valence states...

We have theoretically determined the absorption oscillator strengths and wavenumbers for rotationally resolved transitions of the c 4 ′ ¹ Σ u ⁺ (6)-X ¹ Σ g ⁺ (0–9) bands of N 2 , which are relevant to analyze the spectra of planetary atmospheres. The Molecular Quantum Defect Orbital method has been used in our calculations. The interaction between...

Vertical excitation energies belonging to several Rydberg series of MgH have been inferred from 3+ electron-propagator calculations of the electron affinities of MgH⁺ and are in close agreement with experiment. Many electronically excited states with n > 3 are reported for the first time and new insight is given on the assignment of several Rydberg...

Theoretical transition energies and absorption oscillator strengths for the c(4)'1 Sigma(+)(u) (v'= 0-2, 5, 7, 8) - X-1 Sigma(+)(g) (v" = 0-14) and c(5)('1)Sigma(+)(u) (v' = 0, 2) - X-1 Sigma(+)(g) (v" = 0-14) Rydberg bands, and b'(1)Sigma(+)(u) (v' = 0-9, 11, 12, 14- 19, 21, 22) - X-1 Sigma(+)(g) (v" = 0-14)) valence bands of molecular nitrogen ar...

In this work, electron-propagator methods are applied to the calculation of the ionization potential and vertical excitation energies for several Rydberg series of the CaH molecule. The present calculations cover more highly excited states than those previously reported. In particular, excitation energies for ns (n>5), np (n>5), nd (n>4) and nf Ryd...

Absorption oscillator strengths, calculated with the molecular quantum defect orbital method, for the (3)– = 0–12), (4)– = 0–12), (6)– = 0–12), (10)– = 0–12), (13)– = 0–12), (20)– = 0–12), and (1)– = 0–12) bands of molecular nitrogen are reported. The Rydberg–valence interaction between states of symmetry has been treated through an interaction mat...

Photoionization cross-sections and asymmetry parameters for the outermost orbital of ethanol have been determined with the Molecular Quantum Defect Orbital (MQDO) method. The individual ionization cross-sections corresponding to the Rydberg series that constitute the ionization channels for the production of the molecular cation in its ground state...

Vertical excitation energies of the methyl and silyl radicals were inferred from ab initio electron propagator calculations on the electron affinities of CH3 (+) and SiH3 (+). Photoionization cross sections and angular distribution of photoelectrons for the outermost orbitals of both CH3 and SiH3 radicals have been obtained with the Molecular Quant...

Intensities, expressed as oscillator strengths for the discrete and, as
cross-sections for the continuum electronic spectrum of acetone are
reported. The calculations have been performed with the molecular
quantum defect method (MQDO), which has proved to be a very adequate
tool for this type of studies in other organic molecules. The present
work...

Theoretical cross sections for photoionization of the methanol valence orbitals in covering a region up to 80 eV beyond the first ionization potential are reported. The molecular quantum defect orbital, MQDO, method, which has proved to be reliable in previous applications to molecular photoionization, has been used. To our knowledge, predictions o...

The molecular quantum defect orbital (MQDO) method, previously used in the determination of molecular photoionization cross sections, is applied here to calculate the angular distribution of photoelectrons arising from the molecular photoionization. Calculations are performed for the ionization from outer valence orbitals of HF, H(2)O, NH(3), N(2)O...

The aim of the present theoretical work is to provide data necessary for a better understanding of the electronic spectrum of the silane molecule, which is affected by the Jahn-Teller effect. By selecting an adequate distorted C(2v) geometry of SiH(4), the three lower Koopmans ionization potentials are evaluated with the equation of motion coupled...

Theoretical absorption oscillator strengths and emission branching ratios for rotational lines of the c'{sub 4}{sup 1}{Sigma}{sup +}{sub u}(3)-X{sup 1}{Sigma}{sup +}{sub g}(0-5) bands of molecular nitrogen are reported. The calculations have been performed with the molecular quantum defect orbital method, which has proved to be reliable in previous...

Theoretical absorption oscillator strengths and emission branching ratios for rotational lines of the c'4 1Σ+ u (3)-X 1Σ+ g (0-5) bands of molecular nitrogen are reported. The calculations have been performed with the molecular quantum defect orbital method, which has proved to be reliable in previous studies of rovibronic transitions in diatomic m...

In this work, the linear response formalism with a triples-corrected CCSD reference wave function, LR-CCSDR(3), is applied
to the calculation of vertical excitation energies of singlet states of the F2CO molecule. A basis set of atomic natural orbitals augmented with a series of Rydberg functions has been used in the calculations.
A large number of...

The quantum defect orbital (QDO) method, with the use of a core polarization-corrected dipole transition operator, was employed to determine oscillator strengths for potassium and some of its isoelectronic ions (CaII–CrVI). The inclusion of core-valence polarization effects leads to a general improvement of the QDO f values. Systematic trends of in...

Oscillator strengths for electronic transitions involving Rydberg states of acetaldehyde, as well as cross sections for all
the dipole allowed photoionisation channels, all ending in the ground state of the molecular cation, are reported. The molecular
quantum defect orbital method, which has proved to be reliable in previous applications to molecu...

The vibronic intensities for band systems of NO corresponding to transitions with origin in both the X(2)Pi ground and the 3ssigma(A(2)Sigma(+)) Rydberg states, and ending in the nppi Rydberg series with n = 3-5, have been determined. The description of the Rydberg states has been made with the molecular quantum defect orbital methodology. The Rydb...

Oscillator strengths and integrated cross-sections for rotational lines of the c4′1Σu+(1)-X1Σg+(0-2) bands of N2 have been calculated with the molecular quantum defect orbital (MQDO) method. The known strong homogeneous interaction of the c4′1Σu+(1) Rydberg state with the b′1Σu+(4) valence state has been presently dealt with through an interaction...

Photoionization cross sections for various Rydberg series that correspond to ionization channels of ammonium and oxonium Rydberg radicals from the outermost, occupied orbitals of their respective ground states are reported. These properties are known to be relevant in photoelectron dynamics studies. For the present calculations, the molecular-adapt...

Size-consistent self-consistent multireference singles and doubles configuration interaction (SC)2–MR–SDCI, and linear response coupled cluster of singles and doubles including triples LR–CCSDR(3) methods, with a basis set of ANO’s augmented with a single series of molecular Rydberg functions, have been applied to the calculation of vertical excita...

Theoretical absorption oscillator strengths for transitions involving Rydberg states in molecular formaldehyde as well as cross sections for photoionization Rydberg channels associated with the production of the lowest parent ion electronic state are reported. The calculations have been performed with the molecular quantum defect orbital (MQDO) met...

This study has been focused on the ϵ(0,0) band of the nitric oxide molecule, associated with the absorption electronic transition D2Σ+←X 2Π, in the energetic vacuum ultraviolet region. A temperature of 295 K has been considered. The Molecular Quantum Defect Orbital (MQDO) methodology, with which reliable spectroscopic data have been reached in the...

Absorption oscillator strengths for electronic transitions involving Rydberg states of the CH molecule, as well as photoionization cross sections for the different channels leading to the ground state of the cationic core, CH+, have been calculated with the molecular-adapted quantum defect (molecular quantum defect orbital (MQDO)) method. This mole...

Astrophysically relevant transitions involving excited states in singly ionized nitrogen have been studied, some of them for the first time in the LK-coupling scheme. The Relativistic Quantum Defect Orbital method has been employed. Oscillator strengths and transition probabilities for the fine-structure lines of a number of transition arrays are r...

Hydrogen fluoride has been observed in a number of astrophysical environments, being sizably abundant in some of them, which adds to the interest in the processes in which it participates. The processes that have called for our attention are those that involve the interaction of photons or electrons with HF, as they are largely responsible for the...

The transition intensities supplied in this Letter are directly connected with a description of the discrete and continuum spectrum of BeH. An attempt to meet our goal requires the calculation of the absorption oscillator strengths of several transitions to Rydberg states of BeH, together with differential oscillator strengths which give rise to di...

Vertical excitation energies belonging to some different Rydberg series of hydrogen chloride have been determined with a coupled-cluster theoretical approach. These excitation energies have allowed us to calculate electric dipole transition intensities in HCl and allow additional assessment of the calculation approach presently used to provide an a...

Theoretical absorption oscillator strengths and line-integrated rotational cross sections for both the (0, 0) and (0, 1) bands belonging to the electronic transition of molecular nitrogen, which are relevant to the study of the atmospheres of the Earth, those of planetary satellites, as well as of the interstellar medium, are reported. The calculat...

Oscillator strengths for P, Q and R rotational lines belonging to the (0, v″ = 0, 1) and (1, v″ = 0, 1) bands for the C1Π–X1Σ+ system of HCl have been theoretically studied. The calculations have been performed by following the molecular quantum defect orbital methodology, which has earlier proved to yield accurate intensities for transitions invol...

The photoionization of carbon monoxide from its ground state was studied theoretically. Partial photoionization cross sections were calculated up to a photon energy of 50 eV for the different Rydberg series that constitute the ionization channels of CO from its ground state. These values conform fairly well to the experimental ones found in the lit...

Vertical excitation energies of the Rydberg radical H(3)O are inferred from ab initio electron propagator calculations on the electron affinities of H(3)O(+). The adiabatic ionization energy of H(3)O is evaluated with coupled-cluster calculations. These predictions provide optimal parameters for the molecular-adapted quantum defect orbital method,...

Intensities for the ?(A 2 S + ???X 2 ?), ?(D 2 S + ???X 2 ?) and (D 2 S + ???A 2 S + ) bands for NO have been calculated using the Molecular Quantum Defect Orbital (MQDO) methodology. Radiative lifetimes for the A 2 S + and D 2 S + vibrational Rydberg states have also been determined. The present results are in excellent accord with measurements av...

A detailed description of the P band system of the NO molecule has been achieved by calculating electronic transition moments, Einstein coefficients, and radiative lifetimes. The known strong interaction of the B(2)Pi valence state with Rydberg states of (2)Pi symmetry is treated through a vibronic interaction matrix. This actually implies an exten...

Transitions originating from excited states in copper-like ions have been studied. Fine-structure oscillator strengths obtained with both the quantum defect orbital (QDO) and its relativistic (RQDO) counterpart are reported for 4p 2P – nd 2D (n = 5, 6), 5p 2P – nd 2D (n = 5, 6), and np 2P – 6s 2S (n = 4, 5 ) absorption transitions. © 1992 John Wile...

The diffuse spectral series, 2s2np2P–2s2nd2D, of the boron isoelectronic sequence has been studied through a one-particle scheme, by explicitly treating only the active electron. Oscillator strengths for various transitions (n = 2,3; n´ = 3–16) have been computed with the quantum defect and relativistic quantum defect formalisms, and results compar...

The photoionization of nitric oxide from its ground state has been studied with the molecular-adapted quantum defect orbital (MQDO) method. Partial differential oscillator strengths for the different Rydberg series that constitute the ionization channels of NO from its ground state have been calculated up to a photon energy of 60 eV. The continuity...

Expressions relating explicitly the radiative lifetimes of vibronic states to the electronic transition moment and the absorption oscillator strengths for spin-allowed transitions have been developed for the first time within the molecular quantum defect orbital (MQDO) methodology. Application to the intensities of the (A2Σ+ ← X2Π), ε(D2Σ+ ← X2Π),...

Chaperonins are protein complexes that are believed to function as part of a protein folding system in the cytoplasm of the cell. We observed, however, that the group II chaperonins known as rosettasomes in the hyperthermophilic archaeon Sulfolobus shibatae, are not cytoplasmic but membrane associated. This association was observed in cultures grow...

Los procesos de fotoionización son de una importancia fundamental [1] y encuentran aplicación en un gran número de contextos científicos: Astrofísica [2], química de las radiaciones, biología. Los investigadores de dichos campos, necesitan de valores de fiables de secciones eficaces para la fotoionización parcial, la Fotoabsorción, así como para lo...

Los estados Rydberg moleculares han suscitado en los últimos años un creciente interés entre los espectroscopistas experimentales, motivado en parte por el desarrollo de nuevas técnicas espectroscópicas capaces de investigar estos estados altamente excitados electrónicamente. Los procesos de fotoabsorción que implican estados Rydberg en los derivad...

Since advances in experimental techniques have extended high resolution molecular spectroscopy into the vacuum ultraviolet region, there has been increased interest in Rydberg states of diatomic molecules. For a comprehensive understanding of atomic and molecular electronic spectroscopy and photochemistry, spectra of Rydberg states must be included...

Absorption oscillator strengths for the γ(A2Σ+−X2Π), δ(C2Π−X2Π), and ε(D2Σ+−X2Π) bands of NO, which are relevant to the study of atmospheric processes are reported. We have calculated both electronic and vibronic transition probabilities with the molecular-adapted quantum defect orbital (MQDO) method, which has proved, in previous applications, to...

Einstein coefficients and oscillator strengths for electronic transitions in the Rydberg radical NaHe have been calculated with the molecular-adapted quantum defect orbital (MQDO) method. The correctness of our estimations has been established on the basis of their good agreement with the results of a reliable complex calculation available in the l...

Regularities in the transition intensities along isoelectronic sequences, indi-vidual spectral series, and analogous transitions
in homologous atomic and molecular systems are proving to be very useful in theoretical and experimental investigations of
spectra, as well as for supplying additional data. We have tested such regularities in cal-culatio...

In the present study of the Rydberg spectra of the methyl and silyl radicals, with the molecule-adapted Quantum Defect Orbital (QDO) method, we have sought and found important analogies between the spectral intensities of analogous transitions in these isovalent molecules. Further similarities with the spectra of their isolated central atoms and th...

Extracellular matrix (ECM) polymers secreted by the diatoms Achnanthes longipes Ag. and Cymbella cistula (Ehr.) Kirchn. completely encase the cell and are responsible for adhesion and other interactions with the external environment. To preserve details of the highly hydrophilic ECM in the native state and to preserve, with a high degree of fidelit...

The oscillator strength spectral density for the partial (through different individual Rydberg series) and total photoabsorption processes which determine the photoionization of N2O from its ground state has been studied. Despite its relevance for atmospheric chemistry and astrochemistry, only a few data seem to be available in the literature. The...

In the present work we have studied the Rydberg spectroscopic behavior of the CH3 and SiH3 isovalent radicals. The molecular-adapted quantum defect orbital (MQDO) method has been employed in our calculations, which have been extended to the radicals' isolated central atoms, C and Si. The similarities observed between the intensities of analogous tr...

The size-consistent self-consistent complete active space singles and doubles configuration interaction ((SC)2-CAS-SDCI) procedure has been applied to the calculation of vertical excitation energies, as well as the ionization energy, of the Rydberg radical ArH. Absorption oscillator strengths and Einstein emission coefficients for a number of elect...

Oscillator strengths for fine-structure transitions in the complex atomic systems, neutral selenium, and tellurium, are reported. The calculations were carried out using the relativistic quantum defect orbital method. The resulting oscillator strengths are analyzed in terms of other theoretical and experimental data. In addition, to estimate the co...

Absorption oscillator strengths and photoionization cross sections for electronic transitions involving Rydberg states that are relevant to the photochemistry of N2O and H2CO are reported. These compounds have been found to play an important role in the evolution of Earth's upper atmosphere. However, the difficulties encoutered in both laboratory m...

Transition intensity data on Rydberg electronic transitions of N2O, which are relevant to atmospheric and astrophysical studies, are reported. The calculations have been performed with the molecular-adapted quantum defect orbital method, which has proven to be an adequate theoretical tool in the context of Rydberg spectra. © 2001 John Wiley & Sons,...

In the present study of the Rydberg spectra of the methyl and silyl radicals, with the molecule-adapted Quantum Defect Orbital (QDO) method, we have sought and found important analogies between the spectral intensities of analogous transitions in these isovalent molecules. Further similarities with the spectra of their isolated central atoms and th...

Rydberg-type transitions were observed in the electronic excitation of the 2b2 nonbonding electron in formaldehyde and were therefore accompanied by little vibrational excitation of the ionic core, as suggested by photoelectron spectroscopy on H2CO. A test on the present Molecular Quantum Defect Orbital (MQDO) f-values originating from a given stat...

Astrophysically relevant transitions in the Mg-like ions Si III,
S V and Fe XV have been studied. A J-dependent CIV3
calculation, more extensive than other, earlier ones, has led
to improved accuracy in the calculated energy levels and
oscillator strengths. Independent relativistic quantum defect orbital
and multiconfigurational Dirac-Fock
calculat...

Violet-blue light is toxic to mammalian cells, and this toxicity has been linked with cellular production of H2O2. In this report, we show that violet-blue light, as well as UVA, stimulated H2O2 production in cultured mouse, monkey, and human cells. We found that H2O2 originated in peroxisomes and mitochondria, and it was enhanced in cells overexpr...

Oscillator strengths and Einstein coefficients for a substantial number of transitions in Xe II are reported. The relativistic quantum defect orbital (RQDO) formalism, with and without an explicit correction for core polarization effects has been employed throughout. Two alternative coupling schemes have been followed. A comparative analysis with t...

The mechanism by which epithelial cells rearrange is a process that is central to epithelial morphogenesis, yet remains poorly understood. We have investigated epithelial cell rearrangement in the dorsal hypodermis of the Caenorhabditis elegans embryo, in which two rows of epithelial cells rearrange in a morphogenetic process known as dorsal interc...

Oscillator strengths and Einstein emission coefficients for several Rydberg radicals are reported. The Quantum Defect Orbital (QDO) method has been employed, and comparison is made with the results of more complex theorical procedures.

An integrated approach including TEM, SEM and LM was utilized to investigate adhesives produced by the marine fouling diatom Achnanthes longipes. Extracellular adhesive secretion during sequential attachment in living diatom cells was examined using video microscopy. A suite of cryotechniques including high pressure freezing (HPF), freeze-substitut...

Summary Cell plate formation inChara zeylanica was compared with recent models of cytokinesis in higher plants in order to gain insight into the evolutionary origin of plant cytokinetic processes. Transmission electron microscopy (TEM) reveals that while cytokinesis inC. zeylanica bears many features in common with that in higher plants, there are...

The Quantum Defect Orbital (QDO) method has been applied to the study of transition probabiUties in the oxonium Rydberg radical H3O. Absorption oscillator strengths and Einstein emission coefficients are reported and compared with the results of an earlier, simplified, molecular version of QDO method.

The Relativistic Quantum Defect Orbital (RQDO) method without and with
explicit inclusion of core polarization has been applied to the study of
oscillator strengths of fine structure transitions in neutral chlorine,
some of which are important in interstellar chemistry. The resulting
oscillator strengths are analyzed in terms of other theoretical r...

We have used transmission electron microscopy to examine plasmodesmata of the charophycean green alga Chara zeylanica, and of the putatively early divergent bryophytes Monoclea gottschei (liverwort), Notothylas orbicularis (hornwort), and Sphagnum fimbriatum (moss), in an attempt to learn when seed plant plasmodesmata may have originated. The three...

High pressure freezing enables the rapid arrest of developmental events without prefixation. Standard chemical fixation is a time dependent event and may cause artifacts in sensitive cytoskeletal components. We are studying two developmental events in embryonic Caenorhabditis elegans : that involve changes in the cytoskeleton: spindle alignment and...

Oscillator strengths for $\rm 3s^2\ 3p^2\rightarrow 3s^2\ 3p^1\ 3d^1$ and $\rm 3s^2\ 3p^2\rightarrow 3s^2\ 3p^1\ 4s^1$ transitions in the silicon sequence (KVI - XeXLI) have been calculated using the Relativistic Quantum Defect Orbital (RQDO) method, with and without explicit inclusion of core-valence correlation, and the multiconfigurational Dirac...

Theoretical oscillator strengths for 3s23p 2P-3s23d 2D, 3s23p 2P-3s24s 2S and 3s24s 2S-3s24p 2P fine-structure transitions in some ions of the aluminium isoelectronic sequence are reported. The computations have been carried out with two formalisms within the context of quantum defect theory: the quantum defect orbital method (QDO) and its relativi...

Relativistic Quantum Defect Orbital (RQDO) calculations, with and without explicit account for core-valence correlation, have been performed on the lines corresponding to the 3s-np (n = 3, 4), np-n′d and np-n′s (n = 2, 3; n′ = 3–6) transitions in neutral fluorine, for which transition probability data are particularly scarce.

Transition probabilities corresponding to one-photon transitions to Rydberg states of the methyl radical have been calculated with a molecular-adapted version of the quantum defect orbital (QDO) method. The results appear to be in accord with those of an analysis of the experimental spectrum by Herzberg.

Oscillator strengths for 2s2p3P-2s3d3D and 2s2p3P-2s3s3S fine structure transitions in beryllium-like ions (Z = 4–36) have been calculated using both the Relativistic Quantum Defect Orbital (RQDO) method, with and without explicit inclusion of core-valence correlation, and the multiconfiguration Dirac-Fock (MCDF) approach. Our f-values, which are o...

In a very recent paper [1] we have reported oscillator strengths for fine structure transitions between levels belonging to the diffuse and sharp spectral series in the silver isoelectronic sequence. The calculations were performed with the quantum defect orbital method in both their non-relativistic (QDO) and relativistic (RQDO) formulations, with...

The relativistic quantum defect orbital method has been applied to the study of fine structure 5p
2P-nd
2D and 5p
2P-ns
2S (n≥5) transitions (some of them involving highly excited upper levels) in the silver isoelectronic sequence. The resulting oscillator strengths are analyzed in terms of other relativistic results and some available experimental...

Oscillator strengths and Einstein emission coefficients for electronic transitions in the Rydberg molecule H3O are reported. The calculations have been performed with the Quantum Defect Orbital (QDO) method, and the results are compared with those of an ab initio procedure. © 1995 John Wiley & Sons, Inc.

Theoretical oscillator strengths are reported for the lines of the 4 s4
p 3 P-4 s4 d 3 D transition in some ions of the
zinc isoelectronic sequence, which are of interest in fusion plasma
research. The calculations have been performed with the relativistic
quantum defect orbital (RQDO) method. A core-polarization to the dipole
transitions moment ha...

Relativistic quantum defect orbital (RQDO) calculations, with and without explicit account for core-valence correlation, have been performed on triplet-triplet transition probabilities of several cadmium-like ions. A comparative analysis of our results with the scarce experimental and theoretical data found in the literature is also reported.

The quantum defect orbital (QDO) method and its relativistic (RQDO) counterpart have been employed in this work to compute oscillator strengths for several fine-structure transitions in members of the copper isoelectronic sequence up to Z = 92. The RQDO results are found to be in quite good agreement with the best estimates derived from other sourc...

The quantum defect orbital formalism in both its relativistic and
non-relativistic versions has been applied to the calculation of
oscillator strengths in the sharp spectral series of some boron-like
systems. The results are presented in both tabular and graphical forms.

Relativistic quantum defect orbital (RQDO) calculations, with and without explicit account for corevalence correlation, have been performed on several electron transitions in the zinc and cadmium isoelectronic sequences, which are of interest in astrophysics and fusion plasma research. A comparative study with other theoretical results and experime...

Results of a pilot study on the applicability of the quantum defect orbital method for describing electronic transitions between molecular Rydberg states are reported. Oscillator strengths and Einstein emission coefficients for the triatomic hydrogen molecule have been calculated. The results are in good agreement with the data derived from more so...

Theoretical oscillator strengths are reported for transitions in the diffuse spectral series of some members of the potassium isoelectronic sequence (KI-CrVI). The calculations have been performed with the Quantum Defect Orbital (QDO) method. A core-polarization correction to the dipole transition moment has also been included in the formalism.

The oscillator strengths of the principal spectral series of several members of the sodium isoelectronic sequence, some of which are particularly important in astrophysics and nuclear fusion plasmas, are reported. The computations were carried out using two formalisms within the context of quantum defect theory: the quantum defect orbital method an...

The quantum defect orbital (QDO) method and its relativistic (RQDO) counterpart have been applied to the calculation of oscillator strengths for the 3s 2S → 3p 2Po, 3p 2Po → 3d 2D, 3d 2D → 4f 2Fo, and 3d 2D → 5f 2Fo transitions in sodium-like atoms. The consequences of including relativistic effects are demonstrated.

Nitrous oxide plays an important role in the photochemistry of the Earth's upper atmosphere in spite of its concentration being so low that is commonly classified as a trace constituent. It has been found to be involved in the catalytic destruction of ozone in the stratosphere and to be the main source of odd nitrogen, which regulates the ozone lay...