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In this work, Boron atom adsorption, absorption and diffusion on the surface of and in the bulk of the Nickel are studied with a first-principles density functional theory approach and the climbing image nudged elastic band method. The calculated results indicate that, on the Ni (111) surface, there are three stable sites for B atom adsorption, which are Top site, Hcp-hollow site and Fcc-hollow site, and Hcp-hollow site is the most preferred one. While below the surface, the Boron atom prefers to reside at the Oct site with the absorption energy of −1.38 eV, and the energy barrier for Boron atom diffusing from Hcp-hollow site to Oct site is 1.22 eV. In bulk Ni, the Tet and Oct sites are both stable ones for solution of the B atoms, the energy barrier for B atom diffusing from Tet site to its nearest neighboring Oct site is 0.29 eV, while that for B atom diffusing between two neighboring Oct sites are 1.65 eV, which indicate that the B atom diffuses between two neighboring Oct sites is harder than that from Tet site to neighboring Oct site. [ABSTRACT FROM AUTHOR]

First-principles theory has been applied to study the coadsorption of O 2 and H 2 O on Pt(1 1 1) surface. A series of coadsorption structures were considered in order to determine the most stable configuration. This study shows that the chemisorption state of H 2 O stabilizes the chemisorption state of O 2 , while the physisorption state of H 2 O does not affect the chemisorption state of O 2 . The adsorption reaction pathways for these structures were identified, and the chemisorption state of H 2 O was found to promote the O 2 chemisorption, while the physisorption state of H 2 O hinders the O 2 chemisorption. These results could shed light on the detailed interpretation of the O 2 adsorption processes on Pt(1 1 1) surface. [ABSTRACT FROM AUTHOR]

Abstract: Quantum chemistry calculations at the MP2 and MRCI levels have been used to compute the energies of the stationary points and the minimum energy pathways (MEPs) between them for the dissociation and isomerization reactions of the methylene amido-gene radical. The MEPs for H2CN→ trans-HCNH→ cis-HCNH, H2CN→H+HCN, cis-HCNH→H+{HCN, HNC}, trans-HCNH→H+{HCN, HNC} and collinear CN+H2 →HCN+H are reported. The absence of a transition state for the dissociation of the trans isomer has been verified. Also, some calculations for the concerted H2CN↔H2 +CN are reported. [Copyright &y& Elsevier]

• Octahedral interstice is the most stable position for B atom absorption in W bulk. • Hollow site is the most stable position for B atom adsorption on W surface. • B atom diffuses into W surface shows the bulk diffusion characteristic at last. • Atom diffusion capacity of surface is inverse correlate with atom adsorption ability. • W (1 1 1) surface provides the best condition for B atom diffusion. In this work, adsorption-diffusion behavior of Boron atom along and into W surface as well as the basic Boron atom absorption-diffusion behavior in W bulk were studied using first-principles density functional theory and climbing image nudged elastic band (CI-NEB) method. The result indicates that the octahedral interstice is the most stable position for B atom absorption and the energy barrier for B atom diffusing between two neighboring octahedral interstices in W bulk is 2.476 eV. For the adsorption behavior of Boron atom on W surface, Hollow site is the most stable adsorption position for W (1 0 0) surface and W (1 1 0) surface, while Hollow-II Site is the most stable adsorption position for W (1 1 1) surface. When B atom diffusing along W surface, the energy barrier for B atom diffusing along W (1 0 0) surface is the largest followed by W (1 1 0) surface and W (1 1 1) surface. During B atom diffusion into W surface, the needed energies for B atom diffusing into W (1 0 0) surface, W (1 1 0) surface and W (1 1 1) surface are 2.231 eV, 1.87 eV and 1.63 eV, respectively. After B atom diffuses to the 3rd, 3rd and 4th atomic layer below W (1 0 0) surface, W (1 1 0) surface and W (1 1 1) surface, the subsequent diffusion behavior shows the bulk diffusion characteristic. Beside, atomic diffusion coefficient D indicates that no matter diffusing along or into W surface, W (1 1 1) surface provides the best diffusion condition. [ABSTRACT FROM AUTHOR]