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 On Thu, Jul 7, 2011 at 4:02 PM, Roland Gillen <[email protected]>wrote: > Dear Lily, > > the cutoff energy giverns the fineness of the REAL space 3D grid that is > used to approximate real space integrals of several quantities and for > representation of charge density and potentials etc. > At the other hand, the k-grid is used for discrete integration in > RECIPROCAL space. > > The two grids are unrelated, so there is no direct correlation between the > value of Ecut and the density of the Monkhorst matrix. You will have to do > convergency tests for both parameters. > > Best wishes > Roland > > > > On 7 July 2011 20:33, lily zheng <[email protected]> wrote: > >> Dear all Siesta user, >> >> >> I got one stupid question about energy cutoff and kgrid monkhorst pack. >> Is there any correlation between them? for instance, if value of Ecut >> given, we could estimate k-grid monkhorst matrix? >> >> >> thanks >> >> Lily >> > >
