A finite electric-field approach to evaluate the vertex correction for the screened Coulomb interaction in the quasiparticle self-consistent GW method

We apply the quasiparticle self-consistent GW method (QSGW) to slab models of ionic materials, LiF, KF, NaCl, MgO, and CaO, under electric field. Then we obtain the optical dielectric constants E(Slab) from the differences of the slopes of the electrostatic potential in the bulk and vacuum regions. Calculated E(Slab) show very good agreements with experiments. For example, we have E(Slab)=2.91 for MgO, in agreement with the experimental value E(Experiment)=2.96. This is in contrast to E(RPA)=2.37, which is calculated in the random-phase approximation for the bulk MgO in QSGW. After we explain the difference between the quasiparticle-based perturbation theory and the Greens function based perturbation theory, we interpret the large difference E(Slab)-E(RPA)=2.91-2.37 as the contribution from the vertex correction of the proper polarization which determines the screened Coulomb interaction W. Our result encourages the theoretical development of self-consistent G0W approximation along the line of QSGW self-consistency, as was performed by Shishkin, Marsman and Kresse [Phys. Rev. Lett. 99, 246403(2007)].Comment: 2 figure

Ab initio molecular dynamics investigation of the structure and the noncollinear magnetism in liquid oxygen: Occurrence of O4 molecular units

金沢大学大学院自然科学研究科計算科学金沢大学理学部The ab initio molecular dynamics was performed toinvestigate the noncollinear magnetism of a system with an evolving atomic structure. As such, application to liquid oxygen provides a picture in which the large majority of colliding O2 molecules assume structural and magnetic configurations which closely resemble those in the O4 molecule. Formation of truly long-living molecular O4 units also occurs but involves a considerably smaller fraction of O2 molecules

Ab initio molecular dynamics investigation of the structure and the noncollinear magnetism in liquid oxygen: Occurrence of O4 molecular units

金沢大学理工研究域数物科学系The ab initio molecular dynamics was performed toinvestigate the noncollinear magnetism of a system with an evolving atomic structure. As such, application to liquid oxygen provides a picture in which the large majority of colliding O2 molecules assume structural and magnetic configurations which closely resemble those in the O4 molecule. Formation of truly long-living molecular O4 units also occurs but involves a considerably smaller fraction of O2 molecules

Fully relativistic two-component-spinor approach in the ultrasoft-pseudopotential plane-wave method

金沢大学大学院自然科学研究科計算科学金沢大学理学部We have introduced effects of spin-orbit interaction nonperturbatively to the ultrasoft-pseudopotential scheme accompanied by two component spinor wave functions. Application to the electronic structure calculations of some heavy elements successfully reproduced results of the all electron approaches. The magnetic anisotropy energy and the orbital magnetic moment for alloys, which have shown a good agreement with the previous results, demonstrated broad capabilities of the approach. © 2005 The American Physical Society