Thanks very much, Iurii. I really appreciate your answer and it does make sense to me. With gamma point only it works fine. And, you are right, my system is a solid and I am trying to simulate the optical spectrum. However, I am not sure with the number of atoms (~120 or more) GW-BSE calculations with supercell is actually feasible.
Best, Abhirup ------------------------------------------------------------------------------------------------------------------------------------- Abhirup Patra Postdoctoral Research Fellow Department of Chemistry University of Pennsylvania On Tue, Dec 17, 2019 at 7:50 AM Timrov Iurii <[email protected]> wrote: > Dear Abhirup, > > > As you can see from the error message of the turbo_davidson code, the > k-points algorithm is not supported. Only Gamma point sampling can be used. > > > If I understand correctly, your system is a solid, right? And you want to > use a unit cell with a k-points mesh, right? The turbo_davidson cannot be > used in this case. You may try to use a supercell with a Gamma point > sampling. But be careful when using TDDFT in the adiabatic approximation > for the absorption spectroscopy of solids. I recommend that you check > literature on this topic. Maybe you will need to resort to the BSE approach. > > > HTH > > > Iurii Timrov > > > -- > Dr. Iurii Timrov > Postdoctoral Researcher > STI - IMX - THEOS and NCCR - MARVEL > Swiss Federal Institute of Technology Lausanne (EPFL) > CH-1015 Lausanne, Switzerland > +41 21 69 34 881 > http://people.epfl.ch/265334 > ------------------------------ > *From:* users <[email protected]> on behalf of > Abhirup Patra <[email protected]> > *Sent:* Monday, December 16, 2019 6:12:08 PM > *To:* Quantum ESPRESSO users Forum > *Subject:* [QE-users] k-point algorithm is not tested yet turbo davidson > > Hello, > > I am trying to use turbo_davidson starting from a SCF calculation using > PBE without smearing and spin-polarization. This system is a non-metal with > bandgap of 2.6 eV. I gave uniform k-mesh as follows for the bcc structure > with lattice constant of 10.34 angstrom. > > K_POINTS {crystal_b} > 9 > 0.0 0.0 0.0 0 > 0.0 -0.5 0.0 0 > 0.0 -0.5 0.5 0 > 0.5 -0.5 0.5 0 > 0.5 -0.5 0.0 0 > 0.5 0.0 0.0 0 > 0.0 0.0 0.0 0 > 0.0 0.0 0.5 0 > 0.5 0.0 0.5 0 > > &lr_input > prefix = 'pristine_pbe' > outdir = './' > ! wfcdir = './' > / > &lr_dav > num_eign = 35, > num_init = 70, > num_basis_max = 200, > start = 0.0d0 > finish = 3.5d0 > step = 0.001d0 > broadening = 0.005d0 > / > > However, I am getting the following error: > > Error in routine lr_readin (1): > k-point algorithm is not tested yet > > I am wondering if there is a simple way out to this problem other than > explicitly testing different k mesh combinations. > > Best, > Abhirup > > ------------------------------------------------------------------------------------------------------------------------------------- > Abhirup Patra > Postdoctoral Research Fellow > Department of Chemistry > University of Pennsylvania > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
