Calculation of electronic structures and magnetic moments of Nd2Fe14B and Dy2Fe14B by using linear-combination-of-pseudo-atomic-orbital method

2009 ◽  
Vol 105 (7) ◽  
pp. 07E502 ◽  
Author(s):  
Isao Kitagawa
1970 ◽  
Vol 48 (20) ◽  
pp. 3154-3163 ◽  
Author(s):  
François Tonnard ◽  
Simone Odiot ◽  
Maryvonne L. Martin

A relation between the diamagnetic term for a proton bonded to a carbon atom and the linear combination of atomic orbital charges on C and H is established. Proton diamagnetic terms of some vinyl ethers are calculated, and the conformation of ethoxy group in these molecules studied.


2018 ◽  
Vol 8 (11) ◽  
pp. 2200 ◽  
Author(s):  
Yu Feng ◽  
Zhou Cui ◽  
Ming-sheng Wei ◽  
Bo Wu ◽  
Sikander Azam

Employing first-principle calculations, we investigated the influence of the impurity, Fe atom, on magnetism and electronic structures of Heusler compound Ti2CoSi, which is a spin gapless semiconductor (SGS). When the impurity, Fe atom, intervened, Ti2CoSi lost its SGS property. As TiA atoms (which locate at (0, 0, 0) site) are completely occupied by Fe, the compound converts to half-metallic ferromagnet (HMF) TiFeCoSi. During this SGS→HMF transition, the total magnetic moment linearly decreases as Fe concentration increases, following the Slate–Pauling rule well. When all Co atoms are substituted by Fe, the compound converts to nonmagnetic semiconductor Fe2TiSi. During this HMF→nonmagnetic semiconductor transition, when Fe concentration y ranges from y = 0.125 to y = 0.625, the magnetic moment of Fe atom is positive and linearly decreases, while those of impurity Fe and TiB (which locate at (0.25, 0.25, 0.25) site) are negative and linearly increase. When the impurity Fe concentration reaches up to y = 1, the magnetic moments of Ti, Fe, and Si return to zero, and the compound is a nonmagnetic semiconductor.


1990 ◽  
Vol 213 ◽  
Author(s):  
W. Lin ◽  
Jian-Hua Xu ◽  
A.J. Freeman

ABSTRACTThe electronic structures and cohesive properties of the intermetallics Ni3V, Co3V, and Fe3V in the L12 structure have been studied using the self-consistent total energy linear muffin-tin orbital method based on the local density approximation. The simple rigid-band concept appears to be adequate to explain the structural stability of these compounds. Further,the structural stability of the pseudobinary compounds (Ni,Co,Fe)3V has been investigated based on the rigid-band scheme. The correlation between the electronic concentration and the crystal structure is shown to be related to the fill-up of the bonding states.


2019 ◽  
Vol 10 (48) ◽  
pp. 11041-11053 ◽  
Author(s):  
Adam H. Slavney ◽  
Bridget A. Connor ◽  
Linn Leppert ◽  
Hemamala I. Karunadasa

Explaining most known double perovskite electronic structures and predicting new ones using Linear Combination of Atomic Orbitals analysis.


Author(s):  
Jochen Autschbach

It is shown how an aufbau principle for atoms arises from the Hartree-Fock (HF) treatment with increasing numbers of electrons. The Slater screening rules are introduced. The HF equations for general molecules are not separable in the spatial variables. This requires another approximation, such as the linear combination of atomic orbitals (LCAO) molecular orbital method. The orbitals of molecules are represented in a basis set of known functions, for example atomic orbital (AO)-like functions or plane waves. The HF equation then becomes a generalized matrix pseudo-eigenvalue problem. Solutions are obtained for the hydrogen molecule ion and H2 with a minimal AO basis. The Slater rule for 1s shells is rationalized via the optimal exponent in a minimal 1s basis. The nature of the chemical bond, and specifically the role of the kinetic energy in covalent bonding, are discussed in details with the example of the hydrogen molecule ion.


2018 ◽  
Vol 32 (02) ◽  
pp. 1750362 ◽  
Author(s):  
Jing Xie ◽  
Quan Xie

The electronic structures and magnetic properties of Fe3Si films epitaxial on Si(001) were systematically investigated by using the first-principle calculations on plane-wave pseudo-potential theory. The calculated results show that Fe3Si films epitaxial on Si(001) have the most stable equilibrium state at the lattice constant c = 5.63 Å. The negative heat of formation and cohesive energy of Fe3Si(001)//Si(001) imply that Fe3Si films epitaxial on Si(001) formed in this manner have high structural stability. The calculated spin polarized energy band structures and density of states indicate that Fe3Si films epitaxial on Si(001) have characteristic of metal, whose bonding modes are covalent bond and metallic bond. The band through Fermi level is mainly due to the Fe 3d states and the Si 3p states. Ferromagnetic properties of Fe3Si(001)//Si(001) are attributed to 3d states of the Fe atoms. The atomic magnetic moments of Fe[A,C] and Fe[B] are different from each other, likewise implying Fe3Si films epitaxial on Si(001) is ferromagnetic.


The electronic structures of certain molecules containing oxy-sulphur bonds are analyzed insome detail by means of the molecular orbital method. I t is possible to make rough calculations which, despite the complexity of the system s considered, are nevertheless reasonably reliable. The physical and chemical properties of sulphur dioxide, sulphur trioxide and molecules of the types R 2 SO 2 and R 2 SO are discussed on the basis of these structures. In all these molecules it appears that the oxy-sulphur linkages are best described as double-bonded. A successful correlation between the molecular orbital criterion of bond strengths, namely, the bond orders, and the oxy-sulphur bond force constants may be set up. The measure of agreement attained between observed and predicted properties is quite satisfactory.


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