Has anyone got any ideas why the following (Cu 001) slab flys apart after about 22 iterations?
Tried varying the pseudopotential, starting with the Troullier Martins suggestion. I also tried translating the slab to half way along the z axis (the unit cell is made 20 lattice parameters long along the z axis, so it's 10 lattice parameters up). Same effect - slab sheared in two. If I reduce the z periodicity to approximately the same as the unit cell, the simulation is fine, and in fact converges (forces acting on atoms extremely small) after 1 iteration, so I'm pretty sure the FDF file contains all the correct details. It's when the z periodicity is extended, that's when the problems start... Do I need to make the unit cell variable? I'm guessing this will only improve the x-y dimension, which I dont think is the problem... Thanks Ian **************************************************************** SystemName cu001 SystemLabel cu001 NumberOfAtoms 60 NumberOfSpecies 1 %block ChemicalSpeciesLabel 1 29 CU # Species index, atomic number, species label %endblock ChemicalSpeciesLabel PAO.BasisSize STANDARD PAO.EnergyShift 300 meV PAO.BasisType split %block Ps.lmax CU 3 %endblock Ps.lmax #AtomicCoordinatesOrigin block is in Bohr #1 Bohr = 0.52918 angstroem %block AtomicCoordinatesOrigin 1.205 1.205 1.7037 %endblock AtomicCoordinatesOrigin LatticeConstant 2.55 Ang %block LatticeVectors 5.000 0.000 0.000 0.000 3.000 0.000 0.000 0.000 20.00 %endblock LatticeVectors #MeshCutoff = equivalent plane wave cut-off for grid MeshCutoff 200 Ry MaxSCFIterations 50 DM.MixingWeight 0.3 DM.NumberPulay 4 DM.Tolerance 1.d-3 DM.UseSaveDM SolutionMethod diagon ElectronicTemperature 25 meV MD.TypeOfRun cg MD.NumCGsteps 40 MD.MaxCGDispl 0.1 Ang MD.MaxForceTol 0.04 eV/Ang AtomicCoordinatesFormat ScaledCartesian %block AtomicCoordinatesAndAtomicSpecies 0 0 0 1 1 0 0 1 2 0 0 1 3 0 0 1 4 0 0 1 0 1 0 1 1 1 0 1 2 1 0 1 3 1 0 1 4 1 0 1 0 2 0 1 1 2 0 1 2 2 0 1 3 2 0 1 4 2 0 1 0.5 0.5 0.7071 1 1.5 0.5 0.7071 1 2.5 0.5 0.7071 1 3.5 0.5 0.7071 1 4.5 0.5 0.7071 1 0.5 1.5 0.7071 1 1.5 1.5 0.7071 1 2.5 1.5 0.7071 1 3.5 1.5 0.7071 1 4.5 1.5 0.7071 1 0.5 2.5 0.7071 1 1.5 2.5 0.7071 1 2.5 2.5 0.7071 1 3.5 2.5 0.7071 1 4.5 2.5 0.7071 1 0 0 1.4142 1 1 0 1.4142 1 2 0 1.4142 1 3 0 1.4142 1 4 0 1.4142 1 0 1 1.4142 1 1 1 1.4142 1 2 1 1.4142 1 3 1 1.4142 1 4 1 1.4142 1 0 2 1.4142 1 1 2 1.4142 1 2 2 1.4142 1 3 2 1.4142 1 4 2 1.4142 1 0.5 0.5 2.1213 1 1.5 0.5 2.1213 1 2.5 0.5 2.1213 1 3.5 0.5 2.1213 1 4.5 0.5 2.1213 1 0.5 1.5 2.1213 1 1.5 1.5 2.1213 1 2.5 1.5 2.1213 1 3.5 1.5 2.1213 1 4.5 1.5 2.1213 1 0.5 2.5 2.1213 1 1.5 2.5 2.1213 1 2.5 2.5 2.1213 1 3.5 2.5 2.1213 1 4.5 2.5 2.1213 1 %endblock AtomicCoordinatesAndAtomicSpecies
