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Full-Text Articles in Physics

Selective Detection Of Singlet Gerade Metastable States Of N-2, Wladyslaw Kedzierski, J. W. Mcconkey Jul 2016

Selective Detection Of Singlet Gerade Metastable States Of N-2, Wladyslaw Kedzierski, J. W. Mcconkey

Physics Publications

Metastable N-2 molecules produced by electron impact on N2 are detected using a unique solid nitrogen matrix detector. The time-of-flight system is shown to be selectively sensitive to a(1)Pi(g) and (1)Sigma(+)(g) or (1)Gamma(g) metastable species. The latter species had been identified theoretically previously but was detected experimentally for the first time in the present investigation. Their identification and excitation as a function of electron energy from threshold to 300 eV are presented. Comparison is made with the data obtained by other techniques. Published by AIP Publishing.


Structures Of Neutral And Anionic Au16 Clusters Revisited, Gang Chen, Qian Wang, Qiang Sun, Yoshiyuki Kawazoe, Puru Jena Jan 2010

Structures Of Neutral And Anionic Au16 Clusters Revisited, Gang Chen, Qian Wang, Qiang Sun, Yoshiyuki Kawazoe, Puru Jena

Physics Publications

Using the density functional theory and generalized gradient approximation for exchange and correlation potential, we have performed an extensive search to obtain the ground stategeometries of both neutral and anionic Au16 cluster by considering over 200 low lying isomers. For the neutral Au16 cluster we found a new Td compact structure to be the lowest energy configuration, which is nearly degenerate in total energy with the previously reported Cs and C2v noncage structures. While the Au16− cluster, in agreement with previous calculations, is found to have a Td hollow cage structure, an isomer with a planar structure is found to …


Hydrogen Storage And The 18-Electron Rule, Boggavarapu Kiran, Anil K. Kandalam, Puru Jena Jan 2006

Hydrogen Storage And The 18-Electron Rule, Boggavarapu Kiran, Anil K. Kandalam, Puru Jena

Physics Publications

We show that the 18-electron rule can be used to design new organometallic systems that can store hydrogen with large gravimetric density. In particular, Ti containing organic molecules such as C4H4, C5H5, and C8H8 can store up to 9wt% hydrogen, which meets the Department of Energy target for the year 2015. More importantly, hydrogen in these materials is stored in molecular form with an average binding energy of about 0.55eV∕H2 molecule, which is ideal for fast kinetics. Using molecular orbitals we have analyzed the maximum number of H2 molecules that can be adsorbed as well as the nature of their …


Gold As Hydrogen: Structural And Electronic Properties And Chemical Bonding In Si3au3+/0/- And Comparisons To Si3h3+/0/-, Boggavarapu Kiran, Xi Li, Hua-Jin Zhai, Lai-Sheng Wang Jan 2006

Gold As Hydrogen: Structural And Electronic Properties And Chemical Bonding In Si3au3+/0/- And Comparisons To Si3h3+/0/-, Boggavarapu Kiran, Xi Li, Hua-Jin Zhai, Lai-Sheng Wang

Physics Publications

A single Au atom has been shown to behave like H in its bonding to Si in several mono- and disilicon gold clusters. In the current work, we investigate the Au∕H analogy in trisilicon gold clusters, Si3Au+∕0∕−3. Photoelectron spectroscopy and density functional calculations are combined to examine the geometric and electronic structure of Si3Au−3. We find that there are three isomers competing for the ground state of Si3Au−3 as is the case for Si3H−3. Extensive structural searches show that the potential energy surfaces of the trisilicon gold clusters (Si3Au−3, Si3Au3, and Si3Au+3) are similar to those of the corresponding silicon …


Evolution Of The Electronic Structure Of Be Clusters, V. Cerowski, B. K. Rao, S. K. Khanna, P. Jena, Soh Ishii, Kaoru Ohno, Yoshiyuki Kawazoe Jan 2005

Evolution Of The Electronic Structure Of Be Clusters, V. Cerowski, B. K. Rao, S. K. Khanna, P. Jena, Soh Ishii, Kaoru Ohno, Yoshiyuki Kawazoe

Physics Publications

Using a modified symbiotic genetic algorithm approach and many-body interatomic potential derived from first principles, we have calculated equilibrium geometries and binding energies of the ground-state and low-lying isomers of Be clusters containing up to 41 atoms. Molecular-dynamics study was also carried out to study the frequency of occurrence of the various geometrical isomers as these clusters are annealed during the simulation process. For a selected group of these clusters, higher-energy isomers were more often found than their ground-statestructures due to large catchment areas. The accuracy of the above ground-stategeometries and their corresponding binding energies were verified by carrying out …


Geometry And Electronic Structure Of V-N(Bz)(M) Complexes, Anil K. Kandalam, B. K. Rao, P. Jena, Ravindra Pandey Jan 2004

Geometry And Electronic Structure Of V-N(Bz)(M) Complexes, Anil K. Kandalam, B. K. Rao, P. Jena, Ravindra Pandey

Physics Publications

First-principles calculations based on the generalized gradient approximation to the density functional theory are performed to explore the global geometries, ground-state spin multiplicities, relative stabilities, and energetics of neutral and anionic Vn(Bz)m (n51 – 3, m51 – 4, with n ,m) complexes. The calculated results show that the Vn(benzene)m complexes clearly prefer sandwich structures to rice-ball structures. The ground-state spin multiplicities of the Vn(benzene)n11 complexes increased linearly with the size of the system (i.e., n). In the anionic complexes, the V(benzene)2 complex is found to be unstable against the autodetachment of the extra electron. The energy difference between adiabatic and …


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 …


Electronic Structure And Chemical Bonding Of 3d-Metal Dimers Scx, X=Sc-Zn, G. L. Gutsev, P. Jena, B. K. Rao, S. N. Khanna Jan 2001

Electronic Structure And Chemical Bonding Of 3d-Metal Dimers Scx, X=Sc-Zn, G. L. Gutsev, P. Jena, B. K. Rao, S. N. Khanna

Physics Publications

The electronic and geometrical structures of the ground and excited states of the homonuclear Sc2, mixed ScTi, ScV, ScCr, ScMn, ScFe, ScCo, ScNi, ScCu, and ScZn 3d-metal dimers and their anions have been calculated using the density functional theory with generalized gradient approximation for the exchange-correlation potential. The ground states of the neutral dimers are found to be 5Σ−u (Sc2), 6Σ+ (ScTi), 7Σ+ (ScV), 4Σ+ (ScCr), 3Σ+ (ScMn), 2Δ(ScFe), 1Σ+ (ScCo), 2Σ+ (ScNi), 3Δ(ScCu), and 4Σ+ (ScZn). A natural bond analysis reveals an antiferrimagnetic spin coupling in the ground states of ScCr, ScMn, and ScFe. This is due to the …