Search results for "Dipole"

Sequential Freezing of Quadrupolar and Dipolar Order in (KBr)1-x(KCN)xGlassesa

1986

The magnetic resonance of Gd3+ in Gd2Se3 near the phase transition and up to 300 K

1985

Temperature dependences of the width of the Gd2Sc3 ESR lines are investigated. The observed width is satisfactory explained by a dipole mechanism narrowed by exchange interaction. Changes of the Gd2Se3 ESR line at T = 6 K are due to antiferromagnetic ordering in the sample. Es wird die Temperaturabhangigkeit der ESR-Linienbreite von Gd2Se3 untersucht. Die beobachtete Breite wird durch einen Dipolmechanismus mit Verschmelzung durch Austauschwechselwirkung beschrieben. Anderungen der Gd2Se3-ESR-Linie bei T = 6 K werden infolge antiferromagnetischer Ordnung in der Probe hervorgerufen.

<title>Electro-optical and fluorescence lifetime studies of aminophthalimide probes in liquids</title>

1995

The modified electro-optical absorption and emission methods are described as well as their use for measurements of electrical dipole moments of five aminophthalimides in ground and excited states. It is found that there exists a principal difference between properties of 3- aminophthalimide (3AP) and 4-amino-N-methylphthalimide (4ANMP) in different solvents. The equilibrated dipole moment of 3AP in its excited state is practically independent on the solvent polarity, in comparison with 4ANMP. The possible mechanism of this effect is discussed.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Elektrooptische Emissionsuntersuchungen, III. Das Dipolmoment von trans-p-Dimethylamino-p′-nitrostilben im ersten angeregten Singulettzustand

1977

Aus elektrooptischen Emissions- und Absorptionsuntersuchungen in flussigen und glasig erstarrten Losungen kombiniert mit dielektrischen Untersuchungen konnten u. a. das Dipolmoment und die Polarisierbarkeitskomponente in Richtung des Dipolmoments von trans-p-Dimethylamino-p′-nitrostilben (DMANS) im ersten angeregten Singulettzustand bestimmt werden zu μ0a = (63 ± 5) · 10−30 Cm und α0az = (442 ± 65) · 10−40 CV−1 m2. Es zeigte sich, das die elektrooptischen Absorptions- und Emissionsuntersuchungen an DMANS in unpolaren Losungen zu einem konsistenten Satz von Dipolmomenten fuhren, das also die Aquilibrierung mit der Umgebung nach Anre-gung im unpolaren Cyclohexan keinen Einflus auf das permane…

Stark level crossing and optical-rf double resonance in NaK D 1 Π

1997

We report here (Lambda) -doubling splitting and permanent electric dipole moment d p measurements for a number of vibrotational levels of NaK D 1 II state. Two different methods, which are not Doppler limited, were used. Stark effect induced level crossing was registered as fluorescence polarization changes with external electric field, which allowed us to obtain, from one fit, the values of electric dipole moment and (Lambda) -doubling splitting (Delta) ef between e, f substates of an individual rotational state. Another method consisted in obtaining the ratio (Delta) ef /d p from electric field dependence of the intensity of forbidden line appeared in fluorescence as a result of e- f Star…

Spectral and electrooptical absorption and emission studies on internally hydrogen bonded benzoxazole `double' derivatives: 2,5-bis(benzoxazolyl)hydr…

1999

Abstract Ground and excited state dipole moments and polarizabilities of 2,5-bis(benzoxazolyl)hydroquinone (BBHQ) and 3,6-bis(benzoxazolyl)pyrocatechol (BBPC) are determined by means of electrooptical absorption and emission measurements. BBHQ is found to exhibit a small, while BBPC a large increase of the static polarizability in the Franck–Condon (FC) excited singlet state. The change of the dipole moments upon excitation to the FC state is zero within experimental error. However, both molecules show dipole moments in the fluorescent states of their phototautomers, of about 5 D, the major component being parallel to the long molecular axis. The experimental and theoretical results strongl…

A Theoretical Study of the Electronic Spectra of N9 and N7 Purine Tautomers

1999

The complete active space (CAS) SCF method and multiconfigurational second-order perturbation theory (CASPT2) have been used to study electronic spectra of the N(9)H and N(7)H tautomers of purine. The calculations include vertical excitation energies, oscillator strengths, dipole moments, and transition moment directions in gas phase. In accord with experiment in nonpolar solvents, the two lowest π → π* excited singlet valence states are predicted to be located at 4.7 and 5.1 eV. The latter is expected to shift to the red in aqueous solutions. A satisfactory interpretation of the electronic spectra above 5.5 eV is obtained if the experimental data are assumed to consist of the superposition…

Calculation of size‐intensive transition moments from the coupled cluster singles and doubles linear response function

1994

Coupled cluster singles and doubles linear response (CCLR) calculations have been carried out for excitation energies and dipole transition strengths for the lowest excitations in LiH, CH+, and C4and the results compared with the results from a CI-like approach to equation of motion coupled cluster (EOMCC). The transition strengths are similar in the two approaches for single molecule calculations on small systems. However, the CCLR approach gives size-intensive dipole transition strengths, while title EOMCC formalism does not. Thus, EOMCC calculations can give unphysically dipole transition strengths, e.g., in EOMCC calculations on a sequence of noninteracting LiH systems we obtained a neg…

C3v Top Data System (C3vTDS) software for spectrum simulation of XY3Z symmetric-top molecules using the group chain

2010

Abstract The C3v Top Data System (C3vTDS) program suite has been developed with the aim of studying any rovibrational band or polyad of XY3Z (C3v) symmetric-tops molecules in a singlet electronic state. It is developed in the same way as similar programs for various molecular symmetries (Td, Oh, C4v, C2v and D2h). We work in the O ( 3 ) ⊃ C ∞ v ⊃ C 3 v group chain and this choice has consequences on the method used to specify the input parameters for Hamiltonian and transition moment calculations. One example concerning the ν 2 band of the CH 3 12 D symmetric-top molecule is presented. This package consists in a series of FORTRAN programs called by scripts. The whole package is freely acces…

Modulational instability and two-dimensional dynamical structures

2008

A process of nonlinear structure formation on a two-dimensional lattice is proposed. The basic model consists of a two-dimensional lattice equipped at each node with a molecule or dipole rotating in the lattice plane. The interactions involved in the model are reduced to a periodic lattice. Such a discrete system can be applied to the problem of molecule adsorption on a substrate crystal surface, for instance. The continuum approximation of the model leads to a 2-D sine-Gordon system including nonlinear couplings, which itself can be reduced to a 2-D nonlinear Schrodinger equation in the low amplitude limit. Spatio-temporal structure formation is investigated by means of numerical simulatio…