Dear Winfred, there is nothing wrong in what you are plotting. Indeed, with many atoms and many electrons the density of states increases and, in other words, "states do pack together".
Eventually, in general you want to smoothen out your result so to recover something which is closer to the physically relevant limit of (supposing you are modeling a bulk system) infinitely large system, for which the contribution of individual states would generally be hidden in the system's continuum (think to exceptions like states in gaps). Or you want to take the DOS with a finite resolution. In both cases one smears out the results by attributing to each state a given width (degauss). Also check that the number of energy points in your plot is consistent with the width: i.e., you should have a spacing between the points which is smaller than the width of the peaks. HTH Guido On 26/02/2015 11:11, Winfred Mulwa wrote: > Dear all, > I am doing a pdos calculation of a supercell of 72 atoms and > my nbnd=220 during the nscf calculation. when i draw the graphs > using xmgrace, the states looks packed together. Please assist > where did i go wrong? attached are the graphs for PDOS and > spin polarization. > Regards > Mulwa Winfred. > D Phil Student, Computational Material Science Group, > University of the Free State - QwaQwa, > South Africa. -- Guido Fratesi Dipartimento di Fisica Universita` degli Studi di Milano Via Celoria 16, 20133 Milano, Italy _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
