Hi Hegoi, I wouldn't use MD.PreconditionVariableCell, especially if I didn't understant what it means. Instead, try using a higher cutoff. 150 Ry might be too low, is that what your convergence tests have given you? I would use something in the range 200-300 Ry, unless the tests tell me otherwise. Is portlandite a metal or an insulator?
Cheers, Marcos > Dear All: > > I´m doing my first relaxation with SIESTA and I´ve some problems. > I want to do a simultaneous relaxation of the atomic coordinates and the > lattice parameters of portlandite Ca(OH)2. My problem is that the lattice > parameters decrease alarming, reducing the volume in almost the 30%. I > think the problem is in MD.PreconditionVariableCell paramenter, becouse I > don´t undestand really what does it mean, but I´m not sure. I hope > somebody help me, thank you. > > The input is like this: > > SystemName portlandita > SystemLabel P > NumberOfAtoms 5 > NumberOfSpecies 3 > > %block ChemicalSpeciesLabel > 1 8 O l > 2 1 H > 3 20 CA > %endblock ChemicalSpeciesLabel > %block PAO.Basis > Ca 5 1.90213 > n=3 0 1 E 61.56667 4.61281 > 5.29940 > 1.00000 > n=4 0 2 E 164.86383 5.38785 > 6.76569 4.96452 > 1.00000 1.00000 > n=3 1 1 E 86.94959 3.48034 > 6.32716 > 1.00000 > n=4 1 1 E 112.03339 4.98424 > 7.49434 > 1.00000 > n=3 2 1 E 87.65847 5.83989 > 6.49046 > 1.00000 > H 2 2.72022 > n=1 0 2 E 134.23176 5.88089 > 6.41415 3.59161 > 1.00000 1.00000 > n=2 1 1 E 132.57601 5.96051 > 6.73959 > 1.00000 > O 3 -0.2062 > n=2 0 2 E 89.2503 5.0971 > 5.96175037505551 2.52330170654204 > 1.00000000000000 1.00000000000000 > n=2 1 2 E 76.3408 7.1750 > 1.00000000000000 1.00000000000000 > n=2 2 1 E 104.3073 0.0000 > 3.92324958680187 > 1.00000000000000 > %endblock PAO.Basis > > MD.TypeOfRun CG > MD.VariableCell .true. > MD.NumCGSteps 100 > MD.PreconditionVariableCell 5 Ang > MD.MaxStressTol 1.0 GPa > MD.TargetPressure 0.0 GPa > %block MD.TargetStress > -1.0, -1.0, -1.0, 0, 0, 0 > %endblock MDTargetStress > DM.NumberPulay 5 > DM.NumberKick 4 > > xc.functional GGA > xc.authors PBE > SpinPolarized .true. > MeshCutoff 150.0000000 Ry > OccupationFunction FD > ElectronicTemperature 580 K > > %block kgrid_Monkhorst_pack > 6 0 0 0. > 0 6 0 0. > 0 0 6 0. > %endblock kgrid_Monkhorst_pack > > LatticeConstant 1.0 Ang > %block LatticeParameters > 3.5925 3.5925 4.905 90 90 120 > %endblock LatticeParameters > AtomicCoordinatesFormat Fractional > %block AtomicCoordinatesAndAtomicSpecies > 0.000000 0.000000 0.000000 3 > 0.333333 0.666667 0.233000 2 > 0.666667 0.333333 0.767000 2 > 0.333333 0.666667 0.418000 1 > 0.666667 0.333333 0.582000 1 > %endblock AtomicCoordinatesAndAtomicSpecies > AtomCoorFormatOut ScaledCartesian > END > > > > > > --------------------------------------------------------------------------------------------------------------------------------------------------------------------- > Este mensaje se dirige exclusivamente a su destinatario y puede contener > información privilegiada o confidencial. Si no es vd. el destinatario > indicado, queda notificado de que la utilización, divulgación y/o copia > sin autorización está prohibida en virtud de la legislación vigente. Si ha > recibido este mensaje por error, le rogamos que nos lo comunique > inmediatamente por esta misma vía y proceda a su destrucción. > > Mezu honek eta erantsita dituen agiriek (baldin baditu) isilpeko > informazioa izan dezakete. Hori dela eta, hutsegite baten ondorioz > jasotzen duenak jakin beza bertan dagoen informazioa ezkutukoa dela eta > legeak galarazi egiten duela berori baimenik gabe erabiltzea. > > This message is intended exclusively for its addressee and may contain > information that is CONFIDENTIAL and protected by professional privilege. > If you are not the intended recipient you are hereby notified that any > dissemination, copy or disclosure of this communication is strictly > prohibited by law. If this message has been received in error, please > immediately notify us via e-mail and delete it. > --------------------------------------------------------------------------------------------------------------------------------------------------------------------- > -- Dr. Marcos Verissimo Alves Post-Doctoral Fellow Condensed Matter and Statistical Physics Sector International Centre for Theoretical Physics Trieste, Italy -------- I have become so addicted to vi that I try to exit OpenOffice by typing :wq!
