The random-phase approximation (RPA) for the electron correlation energy, combined with the exact-exchange (EX) energy, represents the state-of-the-art exchange-correlation functional within density-functional theory. However, the standard RPA practice--evaluating both the EX and the RPA correlation energies using Kohn-Sham (KS) orbitals from local or semilocal exchange-correlation functionals-...

Recently we have proposed the extended constrainedsearch sECSd theory in which arbitrary physical quantities can be chosen as basic variables in addition to the electron density.1,2 The validity of this theory has been confirmed by revisiting on the basis of it the spin-density functional theory sSDFTd, the current-density functional theory sCDFTd, the LDA+U method, and the Hartree–Fock–Kohn–Sh...

Because of its useful accuracy and efficiency, density functional theory (DFT) is one of the most widely used electronic structure theories in physics, materials science, and chemistry. Only the exchange-correlation energy is unknown, and needs to be approximated in practice. Exact constraints provide useful information about this functional. The local spin-density approximation (LSDA) was the ...

The present investigation is concerned with sub-impacts taken placed when a rigid hemispherical-head block transversely impacts against a beam at different locations. Dynamic substructure technique for elastic-plastic impact is applied to solve numerically this problem. The time history of impact force and energy exchange between block and beam are obtained. The process of sub-impacts is analyz...

We study the magnetic behavior of ferromagnetic bilayers and how the super-exchange energy affects it. To this end, we compute, for several values of the super-exchange parameters, the final magnetization states of two configurations of bilayered ferromagnetic domains: one made of two stacked thin square plates and the other made of two stacked thin circular plates. We observe numerically the s...

The Aharonov-Vaidman gauge additively transforms the mean energy of a quantum mechanical system into a weak valued system energy. In this paper, the equation of motion of this weak valued energy is used to provide a mathematical statement of an extended 1st Law of Thermodynamics that is applicable to the mean energy of a closed quantum system when the mean energy is expressed in the Aharonov-Va...