Dear Artem, some short comments: 1. You are right, it is a very good idea FIRST get some idea about band structure, well converge things, AND THEN select k-points and functions for plotting, not other way around. 2. In k-points other than Gamma, the wave functions are complex; you should figure out how to plot them in a meaningful way; it may seem cumbersome, though. 3. The number of occupied states in a nonmagnetic dielectric equals (number of valence electrons)/2, i.e. exactly given by chemical composition, prior to any calculation. If magnetic moment is known, getting HOMO and LUMO for each spin channel is equally straightforward. In a metal, this is of course more tricky, as values from one k-point to another.
Best regards Andrei Postnikov > Dear Andrei, > > Thank you very much for your assistance. It seems that I overlooked the > option that you pointed out. > > But, still there is a problem. WaveFuncKPoints block does allow to specify > the k-points at which wavefunctions are calculated. This is how we can > control this aspect at the stage of main Siesta program. But what if I > simply do not know the whole band structure before running Siesta which > means that I do not know the numbers of wavefunctions that I am > potentially > interested in (e.g. I am interested in the bands in vicinity of Fermi > level > but I do not know its value and numbers and values of the corresponding > eigenstates). Also, before having the whole band structure calculated it > is > hard to determine in which k-points I want the wavefunctions to be > calculated. > For this reason, I thought that we could first let Siesta calculate the > whole picture, then visualize the Band Structure and only after that > decide > which k-points and which eigenstates we are interested in. In other words, > we could perform the control at the stage of using Denchar utility without > reducing the outcome of calculations from Siesta. Does it make sense? > > Besides this issue I am not quite sure that I understand the meaning of > option NumberOfEigenStates (*integer*). There is a restriction on that > integer number (greater than the number of occupied states and less than > the > number of basis functions). How can I know the number of occupied states > (even at T=0) before the calculation of Fermi level and "HOMO" band are > done? I suppose that this question is related to the above mentioned. > > I would be very obliged if you could explain this aspect and help me with > my > initial problem. > > Best regards, > > Artem > > > On Sat, May 28, 2011 at 3:52 AM, <[email protected]> wrote: > >> >> > >> > Now MY QUESTION: how to control k-point in which I want the >> wavefunctions >> > to >> > be calculated, and also how to control the number of eigenstate (fist, >> > 31st, >> > etc), for a given k-point, for which I want the wavefunction to be >> > calculated? Does anybody know how to perform that controlling? >> >> Dear Artem, >> I think, the description of the block >> >> WaveFuncKPoints >> >> contains the information you searches? >> (k-points AND wavefunc. numbers to store) >> >> Best regards >> >> Andrei Postnikov >> >> > >> > Many thanks for any help and your time, >> > >> > Artem >> > >> >> >
