[QE-users] band gap calculated from scf vs nscf

Dear QE users, I was computing band gap with solvent effect basing on Environ. But I found the band gap from nscf calculation is much less than the one from scf calculation. This is the case never happened in the calculation without applying solvent effect.  What is the issues leading to the

[QE-users] different band gap calculated from scf and nscf after applying environ

Dear QE users, I get almost exactly same band gap calculated from scf and nscf in normal calculation (2.27 eV), but after applying solvent issue (based on environ), the band gap from scf turns to be 2.95 eV while the one from nscf drops to 1.32 eV. It so confuses me that why there is a differe

[QE-users] convergece error with Environ

Dear QE users, I try to apply solvent effect (water) to my calculation by using Environ. It goes crash as  "from c_bands : error # 1  too many bands are not converged" which isn't encountered before installing Environ. I have tried to increase ecutwfc and change conv_thr from 1.D-6

[QE-users] functional in pseudopotential files for Van der Waal correction

Dear QE users, I am trying to introduce non-local vdw correction to my calculation by using input_dft = 'vdW-DF', which means sla+pw+rpb +vdw1 functionals are used in dft calculation. But only PBE is included in my pseudopotential file. So I want to ask: Are these functionals are all read from

[QE-users] Different kinds of pseudopotentials used in one calculation

Dear QE users, I have a question: Is that forbidden to use two different type of pseudopotentials in one calculation (e.g. Use norm-conserving pseudopotential for C, ultrasoft pseudopotential for O)? Could it produce any error? It will be very appreciated if you can solve my silly problem. Tha

[QE-users] Flat band structure

Dear QE Users,   I am trying to simulation a system with cell parameter represented below:   &SYSTEM     a =  9.66639e+00     b =  1.08037e+01     c =  1.65553e+01     cosab =  1.72500e-01     cosac =  1.52180e-01     cosbc =  1.69516e-02     ibrav = 14     nat   = 182     ntyp  = 5

Re: [QE-users] band convergece problem in charged system

Dear Thomas,   Thanks for your reply. I tried the neutral system before the charge one, which is simulated with Martyna-Tuckerman correction. The good thing is the band gap could achieve convergence in respect of super cell size. And I found that there is band gap between band 104 and 105 abou

[QE-users] LDA+U U value calculation

Dear QE users,   I am using QE-6.4.1. I need to apply LDA+U to the eigenvalue calculation of the transition metal oxide(Mo8O26). There is parameter Hubbard_alpha used for calculate the U value. But I don't know the detailed procedures to obtain U value. It will be very appreciated if someone c

[QE-users] band convergece problem in charged system

Dear QE users: I try to use QE-6.4.1 to simulate as single molecule. The system is built in large super cell, and total_charge=-4  is added to input file leading to charged system. When I do the convergence test in term of the super cell size (20 Angs - 30 Angs ), the variation for total ener