Is there an energy barrier between the minimum found by relax and the one you find varying the angle ?
stefano (sent from my phone) > On 18 Apr 2017, at 21:54, sarashs <[email protected]> wrote: > > They use exactly the same cuttoffs, K-points and everything > (unfortunately.) but the near equilibrium energies are slightly less > than equilibrium one. For instance for SiOZr angle at equilibrium I get: > > ! total energy = -245.22924923 Ry > Harris-Foulkes estimate = -245.22924923 Ry > estimated scf accuracy < 3.9E-12 Ry > > The total energy is the sum of the following terms: > > one-electron contribution = -715.79581276 Ry > hartree contribution = 369.08543112 Ry > xc contribution = -57.16353294 Ry > ewald contribution = 158.66552815 Ry > Dispersion Correction = -0.02086281 Ry > > And for SiOZr angle at equiliberium-25 I get: > > ! total energy = -245.23454839 Ry > Harris-Foulkes estimate = -245.23454839 Ry > estimated scf accuracy < 1.7E-12 Ry > > The total energy is the sum of the following terms: > > one-electron contribution = -739.45020087 Ry > hartree contribution = 380.81843421 Ry > xc contribution = -57.19470926 Ry > ewald contribution = 170.61520075 Ry > Dispersion Correction = -0.02327322 Ry > > Which is similar in terms of total energy but slightly lower and that's > weird. Is there anything I can do to force QE to use the same basis set > throughout SCF calculations? > > >>> On Tuesday, 18 April 2017 17:10:25 CEST sarashs wrote: >>> the other SCF's not have higher energy than the >>> equilibrium angle regardless of them being optimized with a >>> constraint? >>> I mean if the structure is originally relax (which it is) then one >>> expects other near equilibrium structures to have higher energies. Am >>> I >>> wrong there? >> >> You are right. >> >> They should be higher, which usually means less negative. As long as >> the same >> pseudopotentials, cutoffs, k-points and everything else is used. >> >> Do they? > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
