[Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

Dear Wien Users I have a material with an experimental gap value of 0.1 ev and when using different methods I found values far from this value as follows: * mBJ method: - The original BJ parametrization : Eg=0.06 ev ---> There is no parameter to manipulate - The modified BJ para

Re: [Wien] vec2old_lapw

Hi Dear All Wien2k users. really thanks Dr. Martin Kroeker for your reply. now vec2old_lapw works after your advice. with best regards.  ** Nacir GUECHI Dr. Physique de la matière solide.Enseignant-Chercheur à l'université du Dr. Yahia FARES de

[Wien] case.inop output issue

Dear Users, I am running an orthorhombic case (a, b and c are different) I used the following case.inop 9 1 number of k-points, first k-point -5.0 3.0 Emin, Emax for matrix elements, NBvalMAX 3 number of choices (columns in *outmat): 2: hex or tetrag. case 1

Re: [Wien] Hartree-Fock and the Hubbard Model

Hi, DFT+U is a cheap but rather rough approximation of HF. Beside this, there is also the difference that in DFT+U, the Coulomb operator is attenuated in order to account for the screening due to correlation. In HF, no correlation is included. In hybrids, the screening is included by using only ~

Re: [Wien] Hartree-Fock and the Hubbard Model

Dear Pablo, experts in strongly correlated systems may correct me but my understanding is that Hubbard U is not a "model" of Hartree Fock exchange. HF is an approximative treatment of electron-electron interaction, a many body problem. Hubbard model (where U was originally introduced) tries to