To explore atomic-level phenomena in the Cu-Ni-Sn alloy,a second nearest-neighbor modified embedded-atom method(2NN MEAM)potential has been developed for the Cu-Ni-Sn system,building upon the work of other researchers...To explore atomic-level phenomena in the Cu-Ni-Sn alloy,a second nearest-neighbor modified embedded-atom method(2NN MEAM)potential has been developed for the Cu-Ni-Sn system,building upon the work of other researchers.This potential demonstrates remarkable accuracy in predicting the lattice constant,with a relative error of less than 0.5%when compared to density functional theory(DFT)results,and it achieves a 10%relative error in the enthalpy of formation compared to experimental data,marking substantial advancements over prior models.The bulk modulus is predicted with a relative error of 8%compared to DFT.Notably,the potential effectively simulates the processes of melting and solidification of Cu-15Ni-8Sn,with a simulated melting point that closely aligns with the experimental value,within a 7.5%margin.This serves as a foundation for establishing a 2NN MEAM potential for a flawless Cu-Ni-Sn system and its microalloying systems.展开更多
Al,Ca,and Zn are representative commercial alloying elements for Mg alloys.To investigate the effects of these elements on the deformation and recrystallization behaviors of Mg alloys,we develop interatomic potentials...Al,Ca,and Zn are representative commercial alloying elements for Mg alloys.To investigate the effects of these elements on the deformation and recrystallization behaviors of Mg alloys,we develop interatomic potentials for the Al-Ca,Al-Zn,Mg-Al-Ca and Mg-Al-Zn systems based on the second nearest-neighbor modified embedded-atom method formalism.The developed potentials describe structural,elastic,and thermodynamic properties of compounds and solutions of associated alloy systems in reasonable agreement with experimental data and higher-level calculations.The applicability of these potentials to the present investigation is confirmed by calculating the generalized stacking fault energy for various slip systems and the segregation energy on twin boundaries of the Mg-Al-Ca and Mg-Al-Zn alloys,accompanied with the thermal expansion coefficient and crystal structure maintenance of stable compounds in those alloys.展开更多
Using density functional theory, geometries and vibrational frequencies of linear chains NC2nN and HC2n＋1N （n = 1 - 10） have been investigated. Time-dependent density functional theory （TD-DFF） has been used to c...Using density functional theory, geometries and vibrational frequencies of linear chains NC2nN and HC2n＋1N （n = 1 - 10） have been investigated. Time-dependent density functional theory （TD-DFF） has been used to calculate the vertical transition energies and oscillator strengths for the x^1∑g^＋→I^1∑u^＋ transition in NC2,N （n = 1 -10） and X^1∑ → I^1∑^＋ transition in HC2n＋1N （n =1 -7）. On the basis of present calculations, the explicit expressions for the size dependence of the excitation energy and the first adiabatic ionization energy in both carbon chains have been suggested.展开更多
基金sponsored by the Science and Technology Foundation of Guizhou Provincial Education Department(No.QJJ[2024]60)Guizhou Provincial Basic Research Program(Natural Science)(No.QKHJC[2024]Youth 214)+1 种基金Science and Technology Foundation of Guizhou Minzu University(No.GZMUZK[2024]QD21)Research Projects of Anshun University(No.asxybsjj202413).
文摘To explore atomic-level phenomena in the Cu-Ni-Sn alloy,a second nearest-neighbor modified embedded-atom method(2NN MEAM)potential has been developed for the Cu-Ni-Sn system,building upon the work of other researchers.This potential demonstrates remarkable accuracy in predicting the lattice constant,with a relative error of less than 0.5%when compared to density functional theory(DFT)results,and it achieves a 10%relative error in the enthalpy of formation compared to experimental data,marking substantial advancements over prior models.The bulk modulus is predicted with a relative error of 8%compared to DFT.Notably,the potential effectively simulates the processes of melting and solidification of Cu-15Ni-8Sn,with a simulated melting point that closely aligns with the experimental value,within a 7.5%margin.This serves as a foundation for establishing a 2NN MEAM potential for a flawless Cu-Ni-Sn system and its microalloying systems.
文摘Al,Ca,and Zn are representative commercial alloying elements for Mg alloys.To investigate the effects of these elements on the deformation and recrystallization behaviors of Mg alloys,we develop interatomic potentials for the Al-Ca,Al-Zn,Mg-Al-Ca and Mg-Al-Zn systems based on the second nearest-neighbor modified embedded-atom method formalism.The developed potentials describe structural,elastic,and thermodynamic properties of compounds and solutions of associated alloy systems in reasonable agreement with experimental data and higher-level calculations.The applicability of these potentials to the present investigation is confirmed by calculating the generalized stacking fault energy for various slip systems and the segregation energy on twin boundaries of the Mg-Al-Ca and Mg-Al-Zn alloys,accompanied with the thermal expansion coefficient and crystal structure maintenance of stable compounds in those alloys.
基金This work was supported by the State Key Laboratory of Physical Chemistry of Solid Surfaces (Xiamen University), NSF of Henan Province and NNSF of China (20173042, 20233020, 20473062, 20021002)
文摘Using density functional theory, geometries and vibrational frequencies of linear chains NC2nN and HC2n＋1N （n = 1 - 10） have been investigated. Time-dependent density functional theory （TD-DFF） has been used to calculate the vertical transition energies and oscillator strengths for the x^1∑g^＋→I^1∑u^＋ transition in NC2,N （n = 1 -10） and X^1∑ → I^1∑^＋ transition in HC2n＋1N （n =1 -7）. On the basis of present calculations, the explicit expressions for the size dependence of the excitation energy and the first adiabatic ionization energy in both carbon chains have been suggested.
