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Abstract: The crystal structures and phase stability of the ternary alloys R 3 T 4+ x Al12− x (R=Y, Ce, Gd, U, Th; T=Fe, Ru) have been investigated using the interatomic potentials obtained by the lattice inversion method. These compounds crystallize in the hexagonal Gd3Ru4Al12-type structure and the calculated lattice constants correspond well with the experiments. Among the four different kinds of Al sites in the structure, the most preferential sites for Fe atoms or Ru atoms are 6h sites. The properties related to lattice vibration, such as the phonon density of states (DOS) and Debye temperature of R 3Fe4Al12, have been evaluated. A qualitative analysis is carried out with the relevant potentials for the vibrational modes, which makes it possible to predict some thermodynamic properties. [Copyright &y& Elsevier]

Abstract: An atomistic study is presented on the phase stability, site preference and lattice constants of the actinide intermetallic compounds Th3Co4+ x Al12− x and U3Co4+ x Al12− x . Calculations are based on a series of interatomic pair potentials related to the actinides and transition metals, which are obtained by a strict lattice inversion method. The lattice constants of Th3Co4+ x Al12− x and U3Co4+ x Al12− x are calculated for different values of x. The site preference of Co atoms at Al sites is also evaluated and the order is given as 6h, 4f, 2b and 12k for Th3Co4+ x Al12− x , and 6h, 4f, 12k and 2b for U3Co4+ x Al12− x . In addition, some simple mechanical properties such as the elastic constants and bulk modulus are investigated for the actinide compounds with complex structures. [Copyright &y& Elsevier]

Abstract: Based on the successful applications of lattice inversion method in many fields, the crystal structure and phase stability of Cr23C6 and Mn23C6 are investigated using the interatomic potentials obtained by lattice inversion method in this research. The calculated atomic coordinates and crystal parameters are in good agreement with the experimental results and the phase stability of Cr23C6 and Mn23C6 are tested by random atom shifts and global deformations. The calculated energy also indicates that the Cr23C6 is more stable than Mn23C6. [Copyright &y& Elsevier]

Abstract: Experimental determination of the cobalt solubility in the three-phase triangle face-centered cubic+Cr7C3 +graphite have been carried out. In the present work these results are compared with atomistic calculations of the solubility of Co in Cr7C3 phase based on ab initio cohesive energies and lattice inversion method. Comparisons are also made with the literature data reported earlier [Köster W, Sperner F. Arch Eisenhuttenwesen 1955;26:555; Thompson ER, Lemkey FD, Metall Trans 1970;1:2799; Sahm PR, Watts DJ. Metall Trans 1971;2:1260; Sahm PR, Lorenz M, Hugi W, Fruhauf V. Mettal Trans 1972;3:1022; Tuma H, Löbl K. Kovove Mater 1971;9:221; Fritscher K. Thermochim Acta 1979;29:357]. [Copyright &y& Elsevier]

Abstract: The stability of the excellent permanent magnetic compound Nd2Fe14B and substitution of Fe in the compound by V, Cr, Mn, Zr and Nb are investigated by using interatomic pair potentials which are converted from lattice-inversion method. Calculation shows that the substitution always makes the cell volume larger, and the increase of the volume is almost linear with substituent concentration. The calculated cohesive energy shows that the preferential order of substitution of Fe is Nb, V, Cr, Mn, Zr. Nevertheless, all the five substituting elements should most preferentially replace Fe in the j2 site, which has the greatest space among all six Fe sites. [Copyright &y& Elsevier]

Abstract: An investigation of the structural and vibrational properties of RFe12−x Ta x (R=Tb, Dy, Ho) compounds has been performed by a series of interatomic pair potentials obtained through the lattice inversion method. Calculated results show Ta atoms can stabilize RFe12−x Ta x with ThMn12-type structure, and Ta atoms substitute for Fe with a strong preference for the 8i sites. The phase stability of the intermetallics RFe12−x Ta x is tested by many means including random atom shift, global deformation and high temperature disturbance under the control of the pair potentials. The calculated lattice parameters are corresponding to the experimental results. In particular, the phonon densities of states for RFe11.5Ta0.5 are first evaluated. A qualitative analysis is carried out with the relevant potentials for the vibrational modes, which makes it possible to predict some properties related to lattice vibration. [Copyright &y& Elsevier]

Abstract: We have investigated the structural properties of Pr2Fe17− x Mn x compounds by using quasi-ab initio pair potentials Φ Fe–Fe(r), Φ Pr–Fe(r), Φ Pr–Pr(r), Φ Pr–Mn(r), Φ Fe–Mn(r) and Φ Mn–Mn(r). In Pr2Fe17– x Mn x , the ternary elements Mn substitute for Fe atoms without changing the crystal structure. The calculated cohesive energy curves show that for all values of x, Mn preferentially substitutes for Fe in the 6c site and randomly substitutes for Fe in the 18f and 18h site. The calculated lattice constants coincide quite well with experimental values. Furthermore, the phonon density, specific heat and vibrational entropy of these compounds are also calculated. It is interesting that simple pair potentials can describe these extremely anisotropic materials. [Copyright &y& Elsevier]

Abstract: The phase stability and site preference of the intermetallics Sm(Co,M)12 (M = Cr, Ti, V, Nb, Fe) are evaluated by using interatomic pair potentials based on Chen''s lattice inversion method. The calculated results show that substituting either Cr, Ti, V, Nb or Fe atoms makes the crystal cohesive energy of Sm(Co,M)12 decrease markedly, proving that these atoms can stabilize Sm(Co,M)12 with ThMn12 structure. The calculated lattice constants coincide quite well with the experimental data. The order of site preference of these ternary elements T is 8i, 8j and 8f with the occupation of 8i corresponding to the greatest energy decreases. The properties related to lattice vibration, such as the phonon densities of states, specific heat and vibrational entropy, are also evaluated. [Copyright &y& Elsevier]

This work offers a study of the structural stability of La2Co17-xTix and (La1-xRx)2Co17-yTiy (R = Sm, Nd) compounds by the inverted ab initio potentials. The Ti atoms substitute for Co without changing the crystal symmetry and preferentially occupy the 6c site. The calculated lattice constants coincide quite well with experimental values. Moreover, the relaxed structure together with the site preference of the Ti atoms substituting for Co or the R atoms substituting for La could give a simple explanation for the variation behavior of Curie temperature. All the results indicate that the potentials are valid for studying the structural properties of the intermetallics. [Copyright &y& Elsevier]

The phase stabilities of the intermetallics Nd2Co17-xTx (T = Fe, Cr), and Nd2(Co1-xFex)17-yCry are tested by including random atom shift, global deformation and high temperature disturbance under control of the pair potentials. The ternary elements T substitute for Co without changing the crystal symmetry and preferentially occupy the 6c site. The calculated structural parameters correspond well to the experimental data. The variation behavior of the Curie temperature of Nd2Co17-xFex and Nd2(Co1-xFex)17-yCry is explained qualitatively by the exchange interaction model. All these prove the effectiveness of ab initio pair potentials obtained through the lattice inversion method in the description of rare-earth materials. [Copyright &y& Elsevier]

The phase stability, site preference and mechanical properties of ThMn12 type rare-earth intermetallic compound R(Co, T)12 (R=Er or Dy, T=V, Ti, Cr, Mo, Mn, Nb, Ni, Cu) are studied via interatomic pair potentials based on Chen’s lattice inversion technique. The results show that the ternary elements can decrease the internal energy and stabilize the ThMn12 structure. The calculations also show that the internal energy is the lowest when the ternary elements occupy the symmetrical 8i site. All of those are in good agreement with the experimental lattice parameters and X-ray diffraction data. The results indicate that the converted pair potentials are valid for studying the structural properties of certain kinds of complex-structured materials. [Copyright &y& Elsevier]

Abstract: The intermetallics M7B3 (M = Rh, Ru) have been studied to ascertain the effect of partial replacement of M by T (T = Fe, Co) on their phase stability and site preference. The calculated results show that Fe or Co atoms preferentially substitute M at the 2b sites. The calculated lattice parameters are in good agreement with the experimental data. We have calculated the electronic density of states and magnetic properties of M7−x T x B3 compounds. Besides, the phonon density of states of M7−x T x B3, the according specific heat, vibrational entropy and Debye temperature are calculated, and a qualitative analysis with pair potentials is also carried out. [Copyright &y& Elsevier]

Abstract: We present an atomistic study on the phase stability, site preference and lattice constants of the rare earth intermetallics Lu2Fe17−x T x (T=Cr, Mn, Ru). The calculated preferential occupation site of ternary element T is found to be the 4f site. The order of site preference is given as 4f, 12k, 12j and 6g for Lu2Fe17−x T x . The calculated lattice parameters are corresponding to the experimental results. We have calculated the magnetic moments of Lu2Fe17−x T x compounds. Results show that the calculated total magnetic moment of Lu2Fe17 compound is M=37.34μB/f.u. In addition, the total and partial phonon densities of states are evaluated first for these complicated structures. [Copyright &y& Elsevier]

Abstract: The new intermetallics Fe23CB6 have been studied to ascertain the effect of ternary element C on the phase stability and site preference. Fe23CB6 may form with Cr23C6 prototype structure, and the carbons atoms are positioned at 4a sites. The calculated lattice constants are found to agree with report in literatures. We have calculated the magnetic moments of Fe22NiB6, Fe23C6, Fe23B6 and Fe23CB6 compounds. Furthermore, the total and partial phonon densities of states are evaluated first for Fe23C6, Fe23B6 and Fe23CB6. The analysis of the inverted potentials explains qualitatively the contributions of different atoms to the vibrational modes. [Copyright &y& Elsevier]

Abstract: A systemic study of the structural properties of the rare-earth intermetallics Lu2(Fe, T)17 (T = Mn, Ru) and their hydrides has been performed by a series of interatomic pair potentials. The site preference of T atoms at Fe sites is evaluated and the order is given as 4f, 12k, 12j and 6g for Lu2(Fe, T)17. The interstitial H atoms only occupy 6h interstitial sites in Lu2(Fe, T)17. The calculated lattice constants agree with a report in the literature. We have calculated the magnetic moments of Lu2(Fe, T)17 compounds. Results showed that the calculated total magnetic moment of Lu2Fe17 compound is M = 37.34 μB/f.u. Furthermore, the total and partial phonon densities of states are evaluated first for Lu2(Fe, T)17 and their hydrides with the hexagonal Th2Ni17-type structure. [Copyright &y& Elsevier]

Abstract: We present an atomistic study on the phase stability, site preference and lattice constants of the rare earth or actinium intermetallics Ce6Rh30Si19 and A6Pt30Si19 (A=Th, U). The calculated preferential occupation site of one Si atom is found to be the 2b site in Ce6Rh30Si19 and A6Pt30Si19. The Si atom is located at the sites 2b with occupancy close to 50%. Our calculated lattice constants agree with a report in the literature. The total and partial phonon densities of states are evaluated first for these complicated defect structures. The analysis of the inverted potentials explains qualitatively the contributions of different atoms to the vibrational modes. [Copyright &y& Elsevier]

Abstract: The structural properties of RCo2Al8 (R = La, Ce and Pr) compounds are simulated by using pair potentials based on ab initio method and lattice-inversion technique. The calculated lattice constants and atomic coordinates are found in good agreement with the experimental values. Further, some simple mechanical properties such as the elastic constants and bulk modulus are investigated for these materials. In particular, the phonon densities of states for RCo2Al8 are first evaluated. A qualitative analysis is carried out with the relevant potentials for the vibrational modes, which makes it possible to predict some properties related to lattice vibration. [Copyright &y& Elsevier]

Abstract: An atomistic simulation of the structural properties of the UCu5TAl6 compounds, where T is Cr, Mn, Fe, has been carried out using interatomic pair potentials based on the lattice inversion method. The calculated lattice parameters are in good agreement with the experimental data. Furthermore, some simple mechanical properties such as the elastic constants and bulk modulus are investigated for these materials. It is noted that, the total and partial phonon densities of states are first evaluated for the UCu5TAl6 compounds with ThMn12-type structure. The analysis for the inverted potentials explains qualitatively the contributions of different atoms to the vibrational modes. [Copyright &y& Elsevier]