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Physics

Physics Publications

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Full-Text Articles in Physical Sciences and Mathematics

Communications: Chain And Double-Ring Polymeric Structures: Observation Of Alnh3n+1− (N=4–8) And Al4h14, Xiang Li, Andrej Grubisic, Kit H. Bowen, Anil K. Kandalam, Boggavarapu Kiran, Gerd Gantefor, Puru Jena Jan 2010

Communications: Chain And Double-Ring Polymeric Structures: Observation Of Alnh3n+1− (N=4–8) And Al4h14, Xiang Li, Andrej Grubisic, Kit H. Bowen, Anil K. Kandalam, Boggavarapu Kiran, Gerd Gantefor, Puru Jena

Physics Publications

A pulsed arc discharge source was used to prepare gas-phase, aluminum hydride cluster anions, AlnHm−, exhibiting enhanced hydrogen content. The maximum number of hydrogen atoms in AlnHm− species was m=3n+1 for n=5–8, i.e., AlnH3n+1−, and m=3n+2 for n=4, i.e., Al4H14−, as observed in their mass spectra. These are the most hydrogen-rich aluminum hydrides to be observed thus far, transcending the 3:1 hydrogen-to-aluminum ratio in alane. Even more striking, ion intensities for AlnHm− species with m=3n+1 and m=3n+2 hydrogen atoms were significantly higher than those of nearby AlnHm− mass peaks for which m<3n+1, i.e., the ion intensities for AlnH3n+1− and for Al4H14− deviated from the roughly bell-shaped ion intensity patterns seen for most AlnHm−species, in which m ranges from 1 to 3n. Calculations based on density functional theory showed that AlnH3n+1− clusters have chain and/or double-ring polymericstructures.


Photoelectron Imaging And Theoretical Investigation Of Bimetallic Bi1–2ga−0–2 And Pb−1–4 Cluster Anions, M. A. Sobhy, J. Ulises Reveles, Ujjwal Gupta, Shiv N. Khanna, A. W. Castleman Jr. Jan 2009

Photoelectron Imaging And Theoretical Investigation Of Bimetallic Bi1–2ga−0–2 And Pb−1–4 Cluster Anions, M. A. Sobhy, J. Ulises Reveles, Ujjwal Gupta, Shiv N. Khanna, A. W. Castleman Jr.

Physics Publications

We present the results of photoelectron velocity-map imaging experiments for the photodetachment of small negatively charged BimGan (m=1–2, n=0–2), and Pbn (n=1–4) clusters at 527 nm. The photoelectron images reveal new features along with their angular distributions in the photoelectron spectra of these clusters. We report the vertical detachment energies of the observed multiple electronic bands and their respective anisotropy parameters for the BimGan and Pbn clusters derived from the photoelectron images. Experiments on the BiGan clusters reveal that the electron affinity increases with the number of Ga atoms from n=0 to 2. The BiGa−2 cluster is found to be …


Structure Of Siau(16): Can A Silicon Atom Be Stabilized In A Gold Cage?, Qiang Sun, Qian Wang, Gang Chen, Puru Jena Jan 2007

Structure Of Siau(16): Can A Silicon Atom Be Stabilized In A Gold Cage?, Qiang Sun, Qian Wang, Gang Chen, Puru Jena

Physics Publications

Nanostructures of Au and Si as well as Au–Si hybrid structures are topics of great current interest from both scientific and technological points of view. Recent discovery of Au clusters having fullerenelike geometries and the possibility of endohedral complexes with Si atoms inside the Au cage opens new possibilities for designing Au–Si nanostructures. Using ab initio simulated annealing method we have examined the stability of Si–Au16 endohedral complex. Contrary to what we believed, we find that the endohedral configuration is metastable and the structure where Si atom binds to the exterior surface of the Au16 cage is the lowest energy …


Periodic Table Of 3d-Metal Dimers And Their Ions, G. L. Gutsev, M. D. Mochena, P. Jena, C. W. Bauchlicher Jr., H. Partridge Iii Jan 2004

Periodic Table Of 3d-Metal Dimers And Their Ions, G. L. Gutsev, M. D. Mochena, P. Jena, C. W. Bauchlicher Jr., H. Partridge Iii

Physics Publications

The ground states of the mixed 3d-metal dimers TiV, TiCr, TiMn, TiFe, TiCo, TiNi, TiCu, TiZn, VCr, VMn, VFe, VCo, VNi, VCu, VZn, CrMn, CrFe, CrCo, CrNi, CrCu, CrZn, MnFe, MnCo, MnNi, MnCu, MnZn, FeCo, FeNi, FeCu, FeZn, CoNi, CoCu, CoZn, NiCu, NiZn, and CuZn along with their singly negatively and positively charged ions are assigned based on the results of computations using density functional theory with generalized gradient approximation for the exchange-correlation functional. Except for TiCo and CrMn, our assignment agrees with experiment. Computed spectroscopic constants (re,ωe,Do) are in fair agreement with experiment. The ground-state spin multiplicities of all …


Experimental And Theoretical Study Of The Photoelectron Spectra Of Mnox-(X=1-3) Clusters, Gennady L. Gutsev, B. K. Rao, P. Jena, Xi Li, Lai-Sheng Wang Jan 2000

Experimental And Theoretical Study Of The Photoelectron Spectra Of Mnox-(X=1-3) Clusters, Gennady L. Gutsev, B. K. Rao, P. Jena, Xi Li, Lai-Sheng Wang

Physics Publications

We report a combined experimental and theoretical investigation of MnO−x and MnOx(x=1–3) clusters. Theoretically, geometrical configurations of various isomers of the clusters were optimized and vertical detachment energies for the anions were evaluated. The ground state of MnO− was predicted to be 5Σ+, followed by an excited state (7Σ+) 0.14 eV higher in energy. The ground state of MnO−2 is 5B2, with a 3B1 isomer 0.15 eV higher. MnO−3 is predicted to be a singlet D3h cluster. Vibrationally resolved photoelectron spectra of MnO−x were measured at several photon energies and under various experimental conditions, and were interpreted based on the …


Evolution Of The Electronic Structure And Properties Of Neutral And Charged Aluminum Clusters: A Comprehensive Analysis, B. K. Rao, P. Jena Jan 1999

Evolution Of The Electronic Structure And Properties Of Neutral And Charged Aluminum Clusters: A Comprehensive Analysis, B. K. Rao, P. Jena

Physics Publications

Density-functional theory with generalized gradient approximation for the exchange-correlation potential has been used to calculate the global equilibrium geometries and electronic structure of neutral, cationic, and anionic aluminumclusters containing up to 15 atoms. The total energies of these clusters are then used to study the evolution of their binding energy, relative stability, fragmentation channels, ionization potential, and vertical and adiabatic electron affinities as a function of size. The geometries are found to undergo a structural change from two dimensional to three dimensional when the cluster contains 6 atoms. An interior atom emerges only when clusters contain 11 or more atoms. …