First-principles calculations of lattice stability of technetium and rhenium
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China;
3. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
4. School of Energy Science and Engineering, Central South University, Changsha 410083, China)
2. Key Laboratory of Nonferrous Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China;
3. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
4. School of Energy Science and Engineering, Central South University, Changsha 410083, China)
Abstract: Lattice constants, total energies and densities of state of technetium(Tc) and rhenium(Re) with different crystalline structures were calculated with the GGA+PBE function, ultra-soft pseudo-potential and plane wave method in first-principles. The results were compared with those of projector augmented wave(PAW) method in first-principles and experimental data. The lattice stability results prove that HCP phase is the most stable phase, which agrees well with those of PAW method in first-principles and CALPHAD method. Further analyses of densities of state also give the same result of lattice stability for HCP-, FCC-, BCC-Tc and Re. Analyses of atomic populations show that the lattice stability of technetium and rhenium is probably related to the electrons in p and d state.
Key words: technetium; rhenium; lattice stability; first principles