Hydrogen cluster

Rev. Lett. 56,1377,1986. Detection of hydrogen clustering in amorphous hydrogenated silicon by a special technique of dipolar spectroscopy, mul-dple-quantum NMR. 

On the other hand, the alternative ADI mechanism views the processes as occurring where the excited neutral species are also first created through excitation processes. Thereafter, a subsequent intracluster neutral-neutral reaction leads to formation of hydrogenated clusters, (NH3)nH. Following excitation (reaction 7), ionization of the radical species then results in the observed protonated clusters ions as depicted as follows ... 

Starting Geometries (in parentheses), Energies, H), Virial Coefficients, r. Squared Gradient Norms, II grad Ip, and Optimized Geometries for the Hydrogen Clusters"... 

K.N. Sloan, E.D. (2004). Stable Low-Pressure Hydrogen Clusters Stored in a Binary Clathrate Hydrate. Science, 306, 469. 

We have applied Pauling s theory to the molecular hydrogen cluster as follows the nonmetallic cluster is well described by the usual Kekule structure (1-2 3-4) (Fig.2), where orbitals 1 and 2 are at one hydrogen molecule and 3 and 4 are at the other one. The synchronized resonance is the mechanism in which the system alternates between structures (1-2 3-4) and (1-4 2-3) (anti-Kekule) (Fig.2), breaking simultaneously the two original covalent bonds and forming two new ones. 

In the case of the hydrogen cluster, we have obtained, through the Pauling s structures, a description of the metallization of the system under pressure, that is completely consistent with other sophisticated ab initio calculations and with experiments. 

The present author found a non-empirical method to describe the antiferromagnetic state of transition metal oxides and hydrogen clusters with a relatively long H-H distance [1-3]. The study used the discrete variational (DV)-Xa molecular orbital theory, which has been successfully applied to analyze properties of... 

Consequently, it has been confirmed that the broad n peak features in the XAS of CB can provide local structure information, especially on the nonbenzenoid structure and/or hydrogenated cluster-edged carbon atoms. 

H atoms are produced by decomposition of H2 at tungsten filaments and the atoms adsorb on graphite under these experimental conditions. The observed nitrogen-hydrogen clusters must be formed by reaction of the impinging nitrogen with adsorbed hydrogen. 

In 1970, Clampiti and Jefferies [106] reported their molecular beam experiments for various ion clusters. For Ne Li", they found the largest peak for m = 1 followed by nearly identical signals for m = 2, 3, 4, 5, 6. The yield of ion clusters decreases abruptly beyond HcgLi". The same result was found for hydrogen clusters (H2) Li. A remarkable feature of the mass spectrum was the relative insignificance of clusters with m > 6. It was concluded [106] that six molecules around an ion probably constitute a complete shell . This result is important in comparison with theoretical studies of Ng Be " ions. 

The two-phase hydrogen clustering persists in films of a-Si H that are alloyed with significant amounts of C, N, F, or B (Reimer et al, 198 Id Shimizu et al., 1983). Even in pure a-C H without silicon the two distinct hydrogen NMR lines remain. 

The second reason helium and possibly hydrogen clusters are special is their capability to transform to a superfluid state. This is a state in which some or all of the component particles are in their lowest quantum state, a state common to all the particles in that state. This is only possible for particles with integral values of their total spin, particles known as bosons. The common isotope He is one such particle. At a sufficiently low temperature, bulk He goes into its superfluid state, in which a finite fraction of the atoms are in their lowest quantum state. This gives the very cold liquid helium special and sometimes dramatic properties, such as the capability to climb walls of a container, and to spout up through a capillary to form a fountain. 

Variational Path Integral Molecular Dynamics Study of Small Para-Hydrogen Clusters... 

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