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Physics Publications

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Full-Text Articles in Physics

Structures And Photoelectron Spectroscopy Of Cu-N(Bo2)(M) - (N, M=1, 2) Clusters: Observation Of Hyperhalogen Behavior, Yuan Feng, Hong-Guang Xu, Weijun Zheng, Hongmin Zhao, Anil K. Kandalam, Puru Jena Jan 2011

Structures And Photoelectron Spectroscopy Of Cu-N(Bo2)(M) - (N, M=1, 2) Clusters: Observation Of Hyperhalogen Behavior, Yuan Feng, Hong-Guang Xu, Weijun Zheng, Hongmin Zhao, Anil K. Kandalam, Puru Jena

Physics Publications

The electronic structures of CuBO2 , Cu(BO2)2 , Cu2(BO2), and Cu2(BO2)2 clusters were investigated using photoelectron spectroscopy. The measured vertical and adiabatic detachment energies of these clusters revealed unusual properties of Cu(BO2)2 cluster. With an electron affinity of 5.07 eV which is larger than that of its BO2 superhalogen (4.46 eV) building-block, Cu(BO2)2 can be classified as a hyperhalogen. Density functional theory based calculations were carried out to identify the ground stategeometries and study the …


First-Principles Study Of Hydrogen Adsorption In Metal-Doped Cof-10, Miao Miao Wu, Qian Wang, Qiang Sun, Puru Jena, Yoshiyuki Kawazoe Jan 2010

First-Principles Study Of Hydrogen Adsorption In Metal-Doped Cof-10, Miao Miao Wu, Qian Wang, Qiang Sun, Puru Jena, Yoshiyuki Kawazoe

Physics Publications

Covalent organic frameworks (COFs), due to their low-density, high-porosity, and high-stability, have promising applications in gas storage. In this study we have explored the potential of COFs doped with Li and Ca metal atoms for storing hydrogen under ambient thermodynamic conditions. Using density functional theory we have performed detailed calculations of the sites Li and Ca atoms occupy in COF-10 and their interaction with hydrogen molecules. The binding energy of Li atom on COF-10 substrate is found to be about 1.0 eV and each Li atom can adsorb up to three H2 molecules. However, at high concentration, Li atoms cluster …


Negative Ions Of Transition Metal-Halogen Clusters, Kalpataru Pradhan, Gennady L. Gutsev, Purusottam Jena Jan 2010

Negative Ions Of Transition Metal-Halogen Clusters, Kalpataru Pradhan, Gennady L. Gutsev, Purusottam Jena

Physics Publications

A systematic density functional theory based study of the structure and spectroscopic properties of neutral and negatively chargedMXn clusters formed by a transition metal atom M (M=Sc,Ti,V) and up to seven halogen atoms X (X=F,Cl,Br) has revealed a number of interesting features: (1) Halogen atoms are bound chemically to Sc, Ti, and V for n≤nmax, where the maximal valence nmax equals to 3, 4, and 5 for Sc, Ti, and V, respectively. For n>nmax, two halogen atoms became dimerized in the neutral species, while dimerization begins at n=5, 6, and 7 for negatively charged clusters containing Sc, Ti, and …


Stabilizing A 22 Karat Nanogolden Cage, Q. Wang, Q. Sun, P. Jena Jan 2009

Stabilizing A 22 Karat Nanogolden Cage, Q. Wang, Q. Sun, P. Jena

Physics Publications

Since the discovery of C60 fullerene, considerable efforts have been devoted to find other elements with similar hollow cage structures. However, search for hollow metallic cages with a diameter similar to that of C60 fullerene has been elusive. We describe a procedure for the rational design of metallic cages by suitably choosing their size, composition, and charge state. A 22 karat nanogolden cage with a diameter of about 8.5 Å and consisting of 12 Al and 20 Au atoms is found to be metastable, which can be stabilized by embedding a Mn4 cluster. In contrast to bulk Mn, which is …


First-Principles Study Of Ferromagnetic Coupling In Zn1-Xcrxte Thin Film, Q. Wang, Q. Sun, P. Jena, Y. Kawazoe Jan 2005

First-Principles Study Of Ferromagnetic Coupling In Zn1-Xcrxte Thin Film, Q. Wang, Q. Sun, P. Jena, Y. Kawazoe

Physics Publications

Using gradient-corrected density functional theory and supercell technique, we have calculated total energies, electronic structure, and magnetic properties of Cr-doped ZnTe in both bulk and thin-film configurations. Calculations with full geometry optimization for a Zn1−xCrxTesupercell were carried out for different Cr concentrations (x=0.095, 0.143, and 0.19) and by varying the sites Cr atoms occupy. We show that the ferromagnetic phase of Zn1−xCrxTe in both bulk and thin film is energetically the most preferable state irrespective of the concentration and∕or site occupation of the Cr atom. The strong hybridization between Cr3d and Te5p states is found to be responsible for the …


Competition Between Linear And Cyclic Structures In Monochromium Carbide Clusters Crcn- And Crcn (N=2-8): A Photoelectron Spectroscopy And Density Functional Study, Hua-Jin Zhai, Lai-Sheng Wang, P. Jena, G. L. Gutsev, C. W. Bauschlicher Jr. Jan 2004

Competition Between Linear And Cyclic Structures In Monochromium Carbide Clusters Crcn- And Crcn (N=2-8): A Photoelectron Spectroscopy And Density Functional Study, Hua-Jin Zhai, Lai-Sheng Wang, P. Jena, G. L. Gutsev, C. W. Bauschlicher Jr.

Physics Publications

Photoelectron spectroscopy (PES) is combined with density functional theory (DFT) to study the monochromium carbide clusters CrC−n and CrCn (n=2–8). Well-resolved PES spectra were obtained, yielding structural, electronic, and vibrational information about both the anionic and neutral clusters. Experimental evidence was observed for the coexistence of two isomers for CrC−2, CrC−3, CrC−4, and CrC−6. Sharp and well-resolved PES spectra were observed for CrC−n (n=4,6,8), whereas broad spectra were observed for CrC−5 and CrC−7. Extensive DFT calculations using the generalized gradient approximation were carried out for the ground and low-lying excited states of all the CrC−n and CrCn species, as well …


H-Substituted Anionic Carbon Clusters Cnh- (N <= 10): Density Functional Studies And Experimental Observations, L. Pan, B. K. Rao, A. K. Gupta, G. P. Das, P. Ayyub Jan 2003

H-Substituted Anionic Carbon Clusters Cnh- (N <= 10): Density Functional Studies And Experimental Observations, L. Pan, B. K. Rao, A. K. Gupta, G. P. Das, P. Ayyub

Physics Publications

We have studied the interaction of hydrogen with small neutral and anionic carbon clusters using density functional calculations. The geometry, stability, and electronic structure of these clusters show an odd–even alternation originating in the bonding nature of the carbon atoms. Our mass spectrometric measurements of the abundance of CnH− (n⩽10) cluster anions produced by gas-feed Cs sputtering from different crystallographic forms of carbon display similar odd–even alternation with the even-n clusters being relatively more abundant. The calculated trend in the adiabatic electron affinities shows a behavior similar to the experimental abundance pattern. We discuss a possible partial suppression of …


Energetics And Electronic Structure Of Carbon Doped Aluminum Clusters, B. K. Rao, P. Jena Jan 2001

Energetics And Electronic Structure Of Carbon Doped Aluminum Clusters, B. K. Rao, P. Jena

Physics Publications

The energetics and the electronic structure of AlnC clusters (n=3, 4, 5; 11, 12, 13) have been studied by a global optimization of their geometry without any symmetry constraint. The total energies of these clusters both in neutral and charged states are calculated using an all-electron basis and the generalized gradient approximation to the density functional theory. While Al4C and Al12C clusters share some characteristic features of closed shell structures, namely enhanced stability and low electron affinity compared to their neighboring sizes, their ionization potentials exhibit different behavior. These decrease steadily from Al3C to Al5C while that of Al12C is …


Structure And Stability Of The Alx And Alx- Species, Gennady L. Gutsev, Puru Jena, Rodney J. Bartlett Jan 1999

Structure And Stability Of The Alx And Alx- Species, Gennady L. Gutsev, Puru Jena, Rodney J. Bartlett

Physics Publications

The electronic and geometrical structures of the ground and low-lying excited states of the diatomic AlX and AlX− series (X=H, Li, Be, B, C, N, O, and F) are calculated by the coupled-cluster method with all singles and doubles and noniterative inclusion of triples using a large atomic natural orbital basis. All the ground-state AlX molecules except for AlF can attach an additional electron and form ground-state AlX− anions. The ground-state AlBe−, AlB−, AlC−, AlN−, and AlO− anions possess excited states that are stable toward autodetachment of an extra electron; AlBe− also has a second excited state. Low-lying excited states …