Dear Leila, if the total energy keeps decreasing, that it is completely normal: it means that you started from an energy saddle point. It may however indicate that your initial crystal structure was wrong.
kind regards On 28/08/17 07:22, [email protected] wrote: > Hi all, > > We are trying to perform vc-relax calculation for a single layer ZnO > sheet in the presence of an oxygen vacancy in a 4*4 suppercell. We have > used espresso-5.4.0. with different psudopotentials such as GGA, > NORMCONS and non relativistic Pseudopotentials: "O.pbe-mt_fhi.upf and > Zn.pbe-mt_fhi.upf, as well as GBRV pseudopotentials: > “o_pbe_v1.2.uspp.F.UPF” and “zn_pbe_v1.uspp.F.UPF”. The calculations do > not return any error. However, convergences of force and pressure do not > occur even after long time running of the calculations. In fact, the > code starts to decrease force and pressure but after a couple of > relaxation steps they increase. I would be grateful if anyone could > kindly give me any piece of advice to solve the problem. > many thanks, > > Leila Eslami > Department of physics, > Islamic Azad University, > Tehran, Iran > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum -- Dr. Lorenzo Paulatto IdR @ IMPMC -- CNRS & Université Paris 6 phone: +33 (0)1 442 79822 / skype: paulatz www: http://www-int.impmc.upmc.fr/~paulatto/ mail: 23-24/423 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05 _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
