Under the precondition your ab-Initio stuff (e.g. Pseudopotentials, PAO.energyshift, k-space sampling) is correctly configured
First thing you could try is using smaller CG steps Second thing you could try is to divide the relaxation process, i.e (i) fix some atoms relax the rest of the system (ii) after this procedure you could relax the whole system. This corresponds to the stepwise relaxation of parts of the system, instead of the whole system And the third thing you could try is to perform the simulations within a variable unit cell. Michael > Hi > > i am trying to make 2 layers of Polyvinyl alcohol > its unit cell has 2 chains of [-CH2CHOH]i.e. 14 atoms using supercell(1 3 > 2) ,lattice parametre (7.83, 2.52, 5.51, 90, 91.7,90) > layers formed if NumCGSteps 0 > but as i go for relaxation with NumCGSteps 500 to 800 > all bond breaks.........chain structure deformed > how can i go for relaxation?what can be reason behind breakage of > structure?strong hydogen bonding? > should i go with change in lattice parameters? > > > > thanks > -- Michael Schuch FB. Physik / AG. Statistische Physik Barbarastrasse 7 49069 Osnabrück
