The influence of alloy composition (Ti, Mn, TiN) on hydrogen diffusion in Fe was studied in detail using SCM-DV-Xα method. The voltage barriers were obtained via calculation on Fe clusters containing the alloy elemen...The influence of alloy composition (Ti, Mn, TiN) on hydrogen diffusion in Fe was studied in detail using SCM-DV-Xα method. The voltage barriers were obtained via calculation on Fe clusters containing the alloy elements such as Ti, Mn as well as the chemical compound TiN respectively. The results showed that Ti element produced deep trap in Fe, decreasing the diffusion coefficient of hydrogen elements, Mn element did not produce deep trap in Fe, decreasing the diffusion coefficient slightly and TiN in Fe produced very deep "trap" decreasing the diffusion coefficient obviously. The calculation results were in agreement with experiment results.展开更多
The electronic structures of atom clusters Ni7O12H122+ and Ni7O12H9-of β-Ni(OH)2 were calculated by quantum chemical DV-Xα method. By analyzing the state densities, orbital populations, net charges and electric char...The electronic structures of atom clusters Ni7O12H122+ and Ni7O12H9-of β-Ni(OH)2 were calculated by quantum chemical DV-Xα method. By analyzing the state densities, orbital populations, net charges and electric charge density differences of the selected clusters, it was indicated that β-Ni(OH)2 was not typical ionic crystal, and the bonds between Ni and O atoms had obvious covalent characteristics. The bonds between H atom and other atoms in the crystal structure were weaker, which ensured that H atoms can easily deintercalate and intercalate into β-Ni(OH)2. The structure of β-Ni(OH)2 was not changed by moderate de-intercalation of H atoms. However, with the excessive de-intercalation of H atoms, the structure of β-Ni(OH)2 changed and the electrochemical active properties were reduced.展开更多
文摘The influence of alloy composition (Ti, Mn, TiN) on hydrogen diffusion in Fe was studied in detail using SCM-DV-Xα method. The voltage barriers were obtained via calculation on Fe clusters containing the alloy elements such as Ti, Mn as well as the chemical compound TiN respectively. The results showed that Ti element produced deep trap in Fe, decreasing the diffusion coefficient of hydrogen elements, Mn element did not produce deep trap in Fe, decreasing the diffusion coefficient slightly and TiN in Fe produced very deep "trap" decreasing the diffusion coefficient obviously. The calculation results were in agreement with experiment results.
文摘The electronic structures of atom clusters Ni7O12H122+ and Ni7O12H9-of β-Ni(OH)2 were calculated by quantum chemical DV-Xα method. By analyzing the state densities, orbital populations, net charges and electric charge density differences of the selected clusters, it was indicated that β-Ni(OH)2 was not typical ionic crystal, and the bonds between Ni and O atoms had obvious covalent characteristics. The bonds between H atom and other atoms in the crystal structure were weaker, which ensured that H atoms can easily deintercalate and intercalate into β-Ni(OH)2. The structure of β-Ni(OH)2 was not changed by moderate de-intercalation of H atoms. However, with the excessive de-intercalation of H atoms, the structure of β-Ni(OH)2 changed and the electrochemical active properties were reduced.
