Characterization of the shallow state of iodine chloride

1984 ◽  
Vol 62 (12) ◽  
pp. 1947-1953 ◽  
Author(s):  
J. C. D. Brand ◽  
D. Bussières ◽  
A. R. Hoy ◽  
S. M. Jaywant
Keyword(s):  
Ground State ◽  
Spectroscopic Constants ◽  
Interaction Matrix ◽  
Electronic Interaction ◽  
Weakly Bound ◽  
Interaction Matrix Element ◽  
Vibrational Levels ◽  
State 1 ◽  
Shallow State

A weakly bound Ω = 1 state of ICl, [Formula: see text], which converges to the ground state 1(2P3/2) + Cl(2P3/2) of the separated atoms, has been identified and characterized. Spectroscopic constants of this state are Te = 17 338.0(13), ωe = 32.85(48), ωexe = 1.272(40), 103Be = 38.2(13), 104αe = 8.89(34), 105γe = −8.1(20) cm−1, and re = 4.01(6) Å. The dissociation energy De = 219.6 cm−1 is consistent with the value predicted for a Morse function, [Formula: see text]. Transitions [Formula: see text] are allowed owing to homogeneous coupling between ã and the well-defined A(3π1) state; in fact, at medium-long range (r = 6–6.5 Å, D–Gν = 20–30 cm−1), the diabatic ã and A curves cross at a small angle. Principal features of the crossing are explained if the electronic interaction matrix element is ca. 4 cm−1, corresponding to weak coupling. Heterogeneous perturbations of the A and ã states in the range D–Gν < 200 cm−1 are attributed to coupling with high vibrational levels of the ground state X(1Σ+).

High-resolution spectroscopy with a CCD array detector: application to the 2880 Å emission band system in I2

1993 ◽  
Vol 71 (10) ◽  
pp. 1645-1654 ◽  
Author(s):  
Joel Tellinghuisen
Keyword(s):  
High Resolution Spectroscopy ◽  
Spectroscopic Constants ◽  
Lower State ◽  
Array Detector ◽  
Weakly Bound ◽  
Ccd Array ◽  
Vibrational Levels ◽  
Discharge Spectrum ◽  
Absolute Energy ◽  
Text Component

The 2880 Å system in the Tesla discharge spectrum of I2 in Ar is reexamined using a CCD array detector to record spectra for both 127I2 and 129I2. This charge-transfer transition terminates on a weakly bound valence state, giving a highly congested spectrum with fine violet-degraded band structure barely perceivable on a pseudocontinuous background. The superior signal-to-noise capabilities of the array detector permit a great improvement in the precision and number of measured bandheads, as compared with previous results obtained from photographically recorded spectra. The new data span a larger range of vibrational levels in the lower state and lead to a change in the previous ν″ numbering by −3 units. Both states can now be located precisely on the absolute energy axis through least-squares fits in which the lower state energy is represented as a near-dissociation expansion. The primary spectroscopic constants (cm−1) are [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] The lower state has a dissociation energy of 287.5 cm−1 and supports 35 bound levels, subject, however, to possible further revision due to a remaining uncertainty of 1 unit in the ν″ numbering. The previous tentative electronic assignment of this system remains in effect: The upper state is likely the [Formula: see text] state that correlates with I−(1S) + I+(3P1), while the lower state is the [Formula: see text] component of the lowest valence 3Πu multiplet.

scholarly journals A Spectroscopic Validation of the Improved Lennard–Jones Model

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3906
Author(s):  
Rhuiago Mendes de Oliveira ◽  
Luiz Guilherme Machado de Macedo ◽  
Thiago Ferreira da Cunha ◽  
Fernando Pirani ◽  
Ricardo Gargano
Keyword(s):  
Ground State ◽  
Experimental Finding ◽  
Noble Gas ◽  
Thermal Conditions ◽  
Spectroscopic Constants ◽  
Weakly Bound ◽  
Potential Models ◽  
Lennard Jones ◽  
Diatomic Systems ◽  
Correct Application

The Lennard–Jones (LJ) and Improved Lennard–Jones (ILJ) potential models have been deeply tested on the most accurate CCSD(T)/CBS electronic energies calculated for some weakly bound prototype systems. These results are important to plan the correct application of such models to systems at increasing complexity. CCSD(T)/CBS ground state electronic energies were determined for 21 diatomic systems composed by the combination of the noble gas atoms. These potentials were employed to calculate the rovibrational spectroscopic constants, and the results show that for 20 of the 21 pairs the ILJ predictions agree more effectively with the experimental data than those of the LJ model. The CCSD(T)/CBS energies were also used to determine the β parameter of the ILJ form, related to the softness/hardness of the interacting partners and controlling the shape of the potential well. This information supports the experimental finding that suggests the adoption of β≈9 for most of the systems involving noble gas atoms. The He-Ne and He-Ar molecules have a lifetime of less than 1ps in the 200–500 K temperature range, indicating that they are not considered stable under thermal conditions of gaseous bulks. Furthermore, the controversy concerning the presence of a “virtual” or a “real” vibrational state in the He2 molecule is discussed.

scholarly journals Computational Characterization of Astrophysical Species: The Case of Noble Gas Hydride Cations

2021 ◽  
Vol 9 ◽  
Author(s):  
María Judit Montes de Oca-Estévez ◽  
Rita Prosmiti
Keyword(s):  
Spectroscopic Data ◽  
Noble Gas ◽  
Basis Sets ◽  
Spectroscopic Constants ◽  
Computational Studies ◽  
Future Studies ◽  
Wide Range ◽  
Vibrational Levels ◽  
High Level

Theoretical–computational studies together with recent astronomical observations have shown that under extreme conditions in the interstellar medium (ISM), complexes of noble gases may be formed. Such observations have generated a wide range of possibilities. In order to identify new species containing such atoms, the present study gathers spectroscopic data for noble gas hydride cations, NgH+ (Ng = He, Ne, Ar) from high-level ab initio quantum chemistry computations, aiming to contribute in understanding the chemical bonding and electron sharing in these systems. The interaction potentials are obtained from CCSD(T)/CBS and MRCI+Q calculations using large basis sets, and then employed to compute vibrational levels and molecular spectroscopic constants for all known stable isotopologues of ground state NgH+ cations. Comparisons with previously reported values available are discussed, indicating that the present data could serve as a benchmark for future studies on these systems and on higher-order cationic noble gas hydrides of astrophysical interest.

X-ray-Triggered Thermoluminescence and Density Functional Theory Characterization of a gem-Diphenyltrimethylenemethane Biradical

2010 ◽  
Vol 63 (9) ◽  
pp. 1342 ◽  
Author(s):  
Hiroshi Ikeda ◽  
Yasunori Matsui ◽  
Ikuko Akimoto ◽  
Ken-ichi Kan'no ◽  
Kazuhiko Mizuno
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Molecular Geometry ◽  
Electronic Interaction ◽  
Γ Irradiation ◽  
Functional Theory ◽  
Excited Triplet ◽  
X Irradiation

Thermoluminescence (TL) from the excited triplet state of a gem-diphenyltrimethylenemethane biradical (34••*) is triggered by X-irradiation at 77 K followed by annealing to ~140 K. The new X-irradiation method reported here is simpler and more convenient than the previously employed γ-irradiation method. The TL spectrum of 34••* is similar to the photoluminescence spectrum of the 1,1-diphenylethyl radical (5•). The results of density functional theory (DFT) and time-dependent-DFT calculations of the ground state biradical 34•• suggest that no significant electronic interaction takes place between the diphenylmethyl and allyl radical moieties owing to its twisted geometry. Accordingly, the results also suggest that the excited state biradical 34••* has a similar molecular geometry and electronic structure as the triplet ground state. Both the experimental and computational results obtained for 34•• and 5• confirm that the main fluorophore of 34••* is the diphenylmethyl radical moiety.

Rotational analysis and deperturbation of the C2Σ+–X2Σ+ band systems of BeH and BeD

1983 ◽  
Vol 61 (4) ◽  
pp. 641-655 ◽  
Author(s):  
R. Colin ◽  
C. Dreze ◽  
M. Steinhauer
Keyword(s):  
Potential Energy ◽  
Ground State ◽  
Substantial Improvement ◽  
Interaction Matrix ◽  
Energy Curve ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Interaction Matrix Element ◽  
Condon Factors ◽  
Potential Energy Minimum

A new C2Σ+–X2Σ+ transition of BeH and BeD is observed in a beryllium are in hydrogen or deuterium gas mixed with argon. The rotational analysis of the most intense of these strongly red degraded bands, which involve ν′ = 0–2 for BeH and ν′ = 0 for BeD, allows one to derive molecular constants for the new C2Σ+ state. The latter has a large internuclear equilibrium distance (re = 2.301 Å) and a shallow potential energy minimum [Formula: see text]. The principal molecular constants determined are:C2Σ+Tc = 30 953.94 cm−1[Formula: see text]Rotational perturbations between the C2Σ+ and A2Π states are observed in the C–X bands of BeH and BeD and in two new A–X bands of BeH (4–4 and 5–5) which have also been observed and analyzed. These perturbations are treated by a matrix approach and yield a value for the interaction matrix element [Formula: see text].The C–X bands analyzed involve the higher vibrational levels of the X2Σ+ state and allow, therefore, a substantial improvement of the ground state molecular constants to be made and a good Rydberg–Klein–Rees (RKR) potential energy curve to be calculated. The limiting curve of the predissociation confirms the previous value of the dissociation energy [Formula: see text] and indicates that a small maximum, less than 200 cm−1, could exist at [Formula: see text] in the ground state potential energy curve.Franck–Condon factors for the C2Σ+–X2Σ+ bands of BeH and BeD are also calculated.

scholarly journals Global potential energy surfaces for the H3+ system. Analytical representation of the adiabatic ground-state 1 1A′ potential

2000 ◽  
Vol 112 (3) ◽  
pp. 1240-1254 ◽  
Author(s):  
Alfredo Aguado ◽  
Octavio Roncero ◽  
César Tablero ◽  
Cristina Sanz ◽  
Miguel Paniagua
Keyword(s):  
Potential Energy ◽  
Ground State ◽  
Potential Energy Surfaces ◽  
Analytical Representation ◽  
Energy Surfaces ◽  
State 1

Consistent characterization of the electronic ground state of Iron (II) Phthalocyanine from valence and core-shell electron spectroscopy

2021 ◽  
Author(s):  
Jonathan Laurent ◽  
John Bozek ◽  
Marc BRIANT ◽  
Pierre Carcabal ◽  
Denis Cubaynes ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ground State ◽  
Electron Spectroscopy ◽  
Organometallic Compound ◽  
Electronic Ground State ◽  
Core Shell ◽  
Shell Electron ◽  
Phthalocyanine Molecule ◽  
Electronic Ground

We studied the Iron (II) Phthalocyanine molecule in the gas-phase. It is a complex transition organometallic compound, for which, the characterization of its electronic ground state is still debated more...

A Multichannel “Potential Curves Hopping” Model for Inelastic Collisions

1986 ◽  
Vol 41 (5) ◽  
pp. 704-714
Author(s):  
D. Campos ◽  
J. M. Tejeiro ◽  
F. Cristancho
Keyword(s):  
Matrix Element ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Inelastic Collisions ◽  
Interaction Matrix ◽  
Quantum Mechanical ◽  
Interaction Matrix Element ◽  
S Matrix ◽  
Hopping Model ◽  
Potential Curves

We introduce a multichannel “potential curves hopping” model and obtain the exact quantum mechanical S-matrix by solving the associated set of coupled second-order ordinary differential equations that describes the inelastic collisions between atomic particles. The only assumption is that the interaction matrix element between each pair of channels (say, γ and β) is of the form Uγβ(r) = Uβγ(r) =: Uγβ δ( r - rγβ), where δ (c) is the Dirac deltafunction, and rγβ and Uγβ are parameters which can be chosen freely.Semiclassical techniques can be incorporated directly in the theory if the Schrödinger equations for the uncoupled channels allow this treatment. The formulation is particularized to the two-channel problem and illustrated with a semiclassical example the He+ + Ne problem at 70.9 eV.

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