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Full-Text Articles in Physical Sciences and Mathematics
First-Principles Study Of Hydrogen Adsorption In Metal-Doped Cof-10, Miao Miao Wu, Qian Wang, Qiang Sun, Puru Jena, Yoshiyuki Kawazoe
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 …
Structures Of Neutral And Anionic Au16 Clusters Revisited, Gang Chen, Qian Wang, Qiang Sun, Yoshiyuki Kawazoe, Puru Jena
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 …
Doping Induced Anisotropic Growth In C60, Miao Miao Wu, Qiang Sun, Puru Jena, Yoshiyuki Kawazoe
Doping Induced Anisotropic Growth In C60, Miao Miao Wu, Qiang Sun, Puru Jena, Yoshiyuki Kawazoe
Physics Publications
Using density functional theory with generalized gradient approximation for exchange and correlation energy, we show that substitution of a Si atom at one of the C sites in C60 not only allows C59Si to have a hydrophobic head with a hydrophilic tail but also the Si atom acts as a seed for anisotropic growth of the heterofullerene. This is demonstrated by interacting C59Si with N7Sc and B8Si. The resulting complex structures exhibit enhanced electric dipole moments and anisotropy. Thus, doping induced anisotropic growth of nanostructures provides a novel route for the synthesis of bifunctional particles with atomic-level control on selectivity …
Interaction Of Gas Molecules With Ti-Benzene Complexes, G. Chen, P. Jena, Y. Kawazoe
Interaction Of Gas Molecules With Ti-Benzene Complexes, G. Chen, P. Jena, Y. Kawazoe
Physics Publications
Using first-principles calculations based on gradient corrected density functional theory, we have studied the interaction of NH3, H2, and O2 with Ti-benzene complexes [Ti(Bz)2 and Ti2(Bz)2]. The energy barriers as the gas molecules approach the Ti-benzene complexes as well as the geometries of the ground state of these interacting complexes were obtained by starting with several initial configurations. While NH3 and H2 were found to physisorb on the Ti(Bz)2 complex, the O2 reacts with it strongly leading to dissociative chemisorption of the oxygen molecule. In contrast all the gas molecules react with the Ti2(Bz)2 complex. These studies indicate that the …
Nitrogen-Induced Magnetic Transition In Small Chromium Clusters, Q. Wang, Q. Sun, B. K. Rao, P. Jena, Y. Kawazoe
Nitrogen-Induced Magnetic Transition In Small Chromium Clusters, Q. Wang, Q. Sun, B. K. Rao, P. Jena, Y. Kawazoe
Physics Publications
Using density functional theory with generalized gradient approximation for exchange and correlation, we show that otherwise antiferromagnetically coupled chromium atoms in very small chromium clusters couple ferromagnetically when doped with a nitrogen atom, thus leading to giant magnetic moments. For example, the magnetic moment of Cr2N is found to be 9μBwhile that of Cr2 is 0μB. Strong bonding between Cr and N atoms brings about this magnetic transition. The Cr atoms nearest neighbor to N couple ferromagnetically with each other and antiferromagnetically with nitrogen. The significance of these results in understanding the ferromagnetic order in Cr-doped GaN is discussed.