The magnetic rotation spectrum of thioformaldehyde: singlet–triplet perturbations in the Ã1A2 state

1982 ◽  
Vol 60 (9) ◽  
pp. 1212-1222 ◽  
Author(s):  
D. J. Clouthier ◽  
D. C. Moule ◽  
D. A. Ramsay ◽  
F. W. Birss
Keyword(s):  
High Resolution ◽  
Vibrational Level ◽  
Interaction Matrix ◽  
Magnetic Rotation ◽  
Matrix Elements ◽  
Selection Rules ◽  
Rotation Spectrum

Singlet–triplet perturbations in the [Formula: see text] and [Formula: see text] bands of the [Formula: see text], system of H2CS have been studied by high resolution absorption and magnetic rotation spectroscopy. Extensive perturbations in the [Formula: see text] band are associated with corresponding activity in the magnetic rotation spectrum. The shifts of the levels are consistent with interaction matrix elements up to ~ 1 cm−1. The selection rules indicate that the zeroth vibrational level of the 1A2 state is perturbed by the 4361 level of the 3A2 state. A number of perturbations are also observed in the [Formula: see text] band.

The magnetic rotation spectrum of formaldehyde: singlet–triplet perturbations in the 41 and 43 levels of the Ã1A2 state of H2CO

1979 ◽  
Vol 57 (8) ◽  
pp. 1224-1232 ◽  
Author(s):  
D. A. Ramsay ◽  
S. M. Till
Keyword(s):  
Absorption Spectrum ◽  
High Resolution ◽  
Rotational Level ◽  
Magnetic Rotation ◽  
Matrix Elements ◽  
Coriolis Interaction ◽  
Near Ultraviolet ◽  
The Matrix ◽  
Rotation Spectrum

A survey of the magnetic rotation spectrum (MRS) of formaldehyde in the near ultraviolet is reported. The [Formula: see text] and [Formula: see text] bands of the [Formula: see text] system are also studied under high resolution. The rR and pP branches of these bands are found to be active and it is noted that the intensities appear to increase more rapidly with increasing Ka in the MRS than in the absorption spectrum. The 43 and 61 levels are in Coriolis interaction at higher Ka values, and some rR branches of the [Formula: see text] band are identified.Several strong lines in the MRS are shown to be associated with rR, rP, pR, and pP lines in the absorption spectrum and to reveal the presence of singlet–triplet perturbations. Only one perturbed rotational level is found in the [Formula: see text] band, but for the [Formula: see text] band several rotational levels are found to exhibit such perturbations, e.g. 190,19, 191,19, 171,16, 102,8, 102,9, 112,9, 173,14, 173,15, 183,15, and 183,16. These perturbations are produced by ΔJ = ΔN = ΔKa = 0 interactions with the 415161 level of the ã3A2 state and by ΔJ = ΔN = 0. ΔKa = ± 1 interactions with the 5161 level. The matrix elements are of the order of 0.01–0.10 cm−1.

High resolution absorption and magnetic rotation studies of the system of formaldehyde-d1

1983 ◽  
Vol 61 (7) ◽  
pp. 1073-1081 ◽  
Author(s):  
D. J. Clouthier ◽  
A. M. Craig ◽  
D. A. Ramsay
Keyword(s):  
High Resolution ◽  
Magnetic Dipole ◽  
Dipole Transition ◽  
Transition Moment ◽  
Magnetic Rotation ◽  
Excited Singlet ◽  
Selection Rules ◽  
Singlet States ◽  
Excited Singlet States ◽  
Dipole Transition Moment

The 410, 430, and 410610 bands of the [Formula: see text] system of HDCO have been reinvestigated in absorption under high resolution. While the results confirm the earlier rotational analyses of Job et al. (1969), arguments are advanced for changing the assignment of the 777 cm−1 interval from ν3′ to ν6′.The bands have also been studied in magnetic rotation. Most of the activity is attributed to the magnetic dipole transition moment between the ground and excited singlet states, but some activity is assigned to singlet–triplet interactions. For the 430 band, a possible mechanism with ΔJ = 0, ΔN = 0, and ΔKa = 0 selection rules has been deduced.

The magnetic rotation spectrum of formaldehyde: singlet–triplet perturbations in the 2141, 2143, 2243, and 2341 levels of the à lA2 state of H2CO

1983 ◽  
Vol 61 (1) ◽  
pp. 6-14 ◽  
Author(s):  
C. M. L. Kerr ◽  
D. C. Moule ◽  
D. A. Ramsay
Keyword(s):  
Magnetic Activity ◽  
Triplet States ◽  
Magnetic Rotation ◽  
Matrix Elements ◽  
Molecular Constants ◽  
Absorption Bands ◽  
Vibrational Assignments ◽  
The Matrix ◽  
Upper Level ◽  
Rotation Spectrum

The absorption spectra and magnetic rotation spectra of the [Formula: see text],[Formula: see text],[Formula: see text], and [Formula: see text] bands of the [Formula: see text] system of formaldehyde have been studied at high resolution. The earlier analyses of the absorption bands have been refined and improved molecular constants obtained. Several singlet–singlet perturbations have been noted and possible mechanisms discussed.The magnetic activity falls into two classes. Three of the bands show limited singlet–singlet activity with characteristics similar to those found earlier for the [Formula: see text] and [Formula: see text] bands. All the bands show singlet–triplet activity which is characterized by the appearance of rR, rP, pR, and PP transitions associated with a common upper level. Tables of perturbed excited-state singlet levels are given. No appreciable shifts of the perturbed levels have been found indicating that the matrix elements are small. For the [Formula: see text] band two perturbation mechanisms are proposed and the vibrational symmetries and energies of the perturbing triplet states are determined. The energies are too high to permit unambiguous vibrational assignments.

The Band System of Propynal: Rotational Analysis of the 0–0 Band Near 4145 Å

1973 ◽  
Vol 51 (17) ◽  
pp. 1810-1814 ◽  
Author(s):  
F. W. Birss ◽  
Ronald Y. Dong ◽  
D. A. Ramsay
Keyword(s):  
High Resolution ◽  
Band System ◽  
Transition Moment ◽  
Magnetic Rotation ◽  
Rotational Analysis ◽  
Molecular Constants ◽  
Rotation Spectrum

The 0–0 band of the [Formula: see text] system of propynal near 4145 Å has been photographed under high resolution and a rotational analysis carried out. The principal molecular constants for the ã3A″ state are (in cm−1):[Formula: see text]Altogether, 1237 lines have been assigned to transitions with ΔKa = 0. The dominant transition moment involves mixing of the ã3A″ state with higher 1A′ states.A simple magnetic rotation spectrum has been obtained and the assignments of the lines discussed.

THE LYMAN BANDS OF MOLECULAR HYDROGEN

1959 ◽  
Vol 37 (5) ◽  
pp. 636-659 ◽  
Author(s):  
G. Herzberg ◽  
L. L. Howe
Keyword(s):  
High Resolution ◽  
Vibrational Level ◽  
Ground State ◽  
Molecular Hydrogen ◽  
Equilibrium Constants ◽  
Dissociation Limit ◽  
Vibrational Levels ◽  
State Formula ◽  
Single Formula ◽  
Vibrational Constants

The Lyman bands of H2 have been investigated under high resolution with a view to improving the rotational and vibrational constants of H2 in its ground state. Precise Bv and ΔG values have been obtained for all vibrational levels of the ground state. One or two of the highest rotational levels of the last vibrational level (v = 14) lie above the dissociation limit. Both the [Formula: see text] and ΔG″ curves have a point of inflection at about v″ = 3. This makes it difficult to represent the whole course of each of these curves by a single formula and therefore makes the resulting equilibrium constants somewhat uncertain. This uncertainty is not very great for the rotational constants for which we find[Formula: see text]but is considerable for the vibrational constants ωe and ωexe for which three-, four-, five-, and six-term formulae give results diverging by ± 1 cm−1. The rotational and vibrational constants for the upper state [Formula: see text] of the Lyman bands are also determined. An appreciable correction to the position of the upper state is found.

Nuclear matrix elements for theCa48two-neutrino double-βdecay from high-resolution charge-exchange reactions

2004 ◽  
Vol 70 (5) ◽  
Author(s):  
S. Rakers ◽  
C. Bäumer ◽  
A. M. van den Berg ◽  
B. Davids ◽  
D. Frekers ◽  
...  
Keyword(s):  
High Resolution ◽  
Charge Exchange ◽  
Nuclear Matrix ◽  
Matrix Elements ◽  
Exchange Reactions

SYMMETRY AND ELECTRO-OPTICAL PROPERTIES OF NANOTUBES

2002 ◽  
Vol 01 (03n04) ◽  
pp. 313-325 ◽  
Author(s):  
M. DAMNJANOVIĆ ◽  
I. MILOŠEVIĆ ◽  
T. VUKOVIĆ ◽  
B. NIKOLIĆ ◽  
E. DOBARDŽIĆ
Keyword(s):  
Carbon Nanotubes ◽  
Optical Properties ◽  
Density Functional ◽  
Tight Binding ◽  
Optical Characteristics ◽  
Optical Transitions ◽  
Matrix Elements ◽  
Selection Rules ◽  
Single Wall Carbon ◽  
Quantum Numbers

The symmetry of single-wall carbon and inorganic tubes is reviewed. For the carbon nanotubes it is used to get the full set of quantum numbers, in the efficient precision (combined density functional and tight-binding methods) calculation of electronic bands and their complete assignation, to obtain the selection rules for optical transitions and the momenta matrix elements for the Bloch eigen-states. The optical characteristics are thoroughly found, and discussed.

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