Dear Heiko,
Thank you sooooo much for your detailed explanation! Definitely it helps! Since i am a newbie for this software, I have lot of questions to struggle with. Especially about PAO and Pseudo potential. For instance, If let me define Block PAO.Basis, how to come up with cutoff radius of each Zeta? It seems there are some ready-made Pseudopotential files. But When I go through the manual, it says that we need keep consistent between pseudo atomic basis and pseudopotential, how to guarantee it? I am not sure I express my question clearly or not. thanks Lily On Fri, Jul 8, 2011 at 1:47 AM, Heiko Dumlich <[email protected]>wrote: > Dear Lily, > > this depends not only on the number of atoms, but also on your system. > > Do you want to calculate a slab, a bulk or a molecule and the elements are > also important. > > Will it be a metallic system or semiconducting ? > > A good idea is to vary your k-grid parameter and see if it converges. > > Range for k-points per axis can be between 1 and 500 (at least that was the > highest I had so far for density of states calculations of "pseudo-metallic" > systems). > > Also consider the accuracy you need/the question you want to answer with > your calculation. > > Maybe you don't need a too good k-point sampling, as you are not interested > in bandstructure and density of states. Therefore an average sampling might > be sufficient. > > Best wishes > > Heiko > > > > > On 07/07/11 23:20, lily zheng wrote: > >> Thank you so much for your explanation,Roland! >> >> Usually what is the thumb of rule to get Monkhorst matrix? for instance, >> if I only calculate 2 atoms system? while if I calculate 1000 atoms >> system, what the monkhorst matrix should be like? >> >> Many thanks >> >> Lily >> > > -- > Heiko Dumlich > Freie Universität Berlin > Fachbereich Physik - AG Reich > Arnimallee 14 > D-14195 Berlin > GERMANY > > Phone: +49-30-838 56157 > >
