Dear Dr. Kawamura thanks a lot for the patch.
Dear Giuseppe, after discussion of our collaborators with Paolo Giannozzi and Stefano De Gironcoli, we learned that it is possible in QE v 6.1 to use tetrahedra for relax and vc-relax calculations for insulators/semiconductors, especially using the the optimized tetrahedron method (occupations='tetrahedra_opt'), as reported in the pw.x manual for version 6.1: Available options are: 'smearing' : gaussian smearing for metals; see variables smearing<http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#smearing> and degauss<http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#degauss> 'tetrahedra' : Tetrahedron method, Bloechl's version: P.E. Bloechl, PRB 49, 16223 (1994)<https://journals.aps.org/prb/abstract/10.1103/PhysRevB.49.16223> Requires uniform grid of k-points, to be automatically generated (see card K_POINTS<http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#K_POINTS>). Well suited for calculation of DOS, less so (because not variational) for force/optimization/dynamics calculations. 'tetrahedra_lin' : Original linear tetrahedron method. To be used only as a reference; the optimized tetrahedron method is more efficient. 'tetrahedra_opt' : Optimized tetrahedron method: see M. Kawamura, PRB 89, 094515 (2014)<https://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.094515>. Can be used for phonon calculations as well. 'fixed' : for insulators with a gap 'from_input' : The occupation are read from input file, card OCCUPATIONS<http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#OCCUPATIONS>. Option valid only for a single k-point, requires nbnd<http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#nbnd> to be set in input. Occupations should be consistent with the value of tot_charge<http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#tot_charge>. Best, Chiara ________________________________ De : [email protected] <[email protected]> de la part de Giuseppe Mattioli <[email protected]> Envoyé : mercredi 18 octobre 2017 10:48:15 À : [email protected] Objet : Re: [Pw_forum] tetrahedra and vc-relax Dear Chiara You should not use occupations='tetrahedra' for relax or vc-relax calculations! The reason is clearly stated in the pw.x manual. Use smearing instead Variable: occupations Type: CHARACTER Description: Available options are: 'smearing' : gaussian smearing for metals; see variables "smearing" and "degauss" 'tetrahedra' : especially suited for calculation of DOS (see P.E. Bloechl, PRB 49, 16223 (1994)). Requires uniform grid of k-points, automatically generated (see below). Not suitable (because not variational) for force/optimization/dynamics calculations. 'fixed' : for insulators with a gap 'from_input' : The occupation are read from input file, card "OCCUPATIONS". Option valid only for a single k-point, requires "nbnd" to be set in input. Occupations should be consistent with the value of "tot_charge". HTH Giuseppe Quoting [email protected]: > Dear all, > > I'm trying to perform a "vc-relax" calculation using the tetrahedron > method with QE v 6.1. > > The calculation stops after having printed the final geometry, > during the final scf step. > > It does not write any error and the scheduler only reports a > segmentation fault. > > I have tried with both tetrahedra and tetrahedra_opt, but I have the > same issue. > > The problem is not there if I do a "relax" calculation. > > Please find attached, the input and output of an example. > > Thanks in advance! > > Regards, > > Chiara Ricca > > --- > > Postdoctoral fellow > > University of Bern GIUSEPPE MATTIOLI CNR - ISTITUTO DI STRUTTURA DELLA MATERIA Via Salaria Km 29,300 - C.P. 10 I-00015 - Monterotondo Scalo (RM) Mob (*preferred*) +39 373 7305625 Tel + 39 06 90672342 - Fax +39 06 90672316 E-mail: <[email protected]> _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
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