It is shown that the "two-libron" lines in the Raman spectrum of solid hydrogen result from the large cubic anharmonicity of the quadrupole-quadrupole Hamiltonian. A localized picture is used to describe the interaction of two librational excitations on neighboring molecules, and dynamic interactions with other molecules are treated perturbatively. In this approximation the average single-libro...

The molecular beam electric resonance technique has been used to examine the hyperfine spectrum of CsF to determine the nuclear quadrupole interaction of the cesium nucleus. A total of 95 transitions in vibrational states v5025 and rotational states J5128 have been included in a fit to determine the cesium nuclear quadrupole and spin–rotation interactions, the fluorine spin–rotation interaction...

Using high-field NMR, we have determined the magnitude of the nuclear quadrupole interaction in hexamethylene triperoxide diamine (HMTD), the explosive allegedly used in the London bombings of July 2005. The experimental quadrupolar coupling constant, 5.334 MHz, is in good agreement with quantum chemical calculations. The predicted single zero-field transition frequency should lie in a relative...

Based on the calculated electric field gradient (q) from ab initio Cl wavefunctions with large basis set (including / functions on N and d functions on H) and the experimental nuclear quadrupole coupling constant (e Q q) for nitrogen in N H 3, an improved value o f the quadrupole moment o f l4N is proposed as Q ('4N ) = 2.08 x 10~ 26 cm2. The value calculated using a wavefunction near the Hartr...

An attempt is made to improve the currently accepted muonic value for the 197Au nuclear quadrupole moment [+0.547(16)x10(-28) m2] for the 3/2+ nuclear ground state obtained by Powers et al. [Nucl. Phys. A230, 413 (1974)]. From both measured Mossbauer electric quadrupole splittings and solid-state density-functional calculations for a large number of gold compounds a nuclear quadrupole moment of...

Stabilizations and atomic level quadrupole coupling constant (CQ) properties have been investigated for graphene–like monolayers (G–monolayers) of boron nitride (BN), boron phosphide (BP), aluminum nitride (AlN), and aluminum phosphide (AlP) structures. To this aim, density functional theory (DFT) calculations have been performed to optimize the model structures and also to evaluate the CQ para...

Ab initio calculations were performed on the series of clusters [(OH)3M-O-M(OH)3](-2) where M = B, Al, and Ga, (OH)3M-O-M(OH)3 where M = C, Si, and Ge, (OH)2OM-O-MO(OH)2 where M = P and As, and (OH)O2M-O-MO2(OH) where M = S and Se. These clusters were constructed to model the effect of changing the coordinating cation and coordinating cation-oxygen distances on the bridging oxygen 17O quadrupol...

Density functional theory (DFT) calculations have been performed to investigating the effects of themolecular oxygen impurity on the quadrupole coupling constant (Qcc) parameters of armchair and zigzagboron nitride nanotubes (BNNTs). Optimization processes have been performed to relax the original andimpure structures of the investigated BNNTs. Afterwards, the Qcc parameters have been evaluated...

The first rotational spectrum of a dinuclear complex, MnRe(CO)(10), has been obtained using a high-resolution pulsed beam microwave spectrometer. Sixty-four hyperfine components of the J=11-->J(')=12 and J=12-->J(')=13 rotational transitions were measured for two rhenium isotopomers. The B values obtained from the experiment are B=200.36871(18) MHz for the (187)Re isotopomer and B=200.5561(10) ...