<div dir="ltr">I have a rather large unit cell(160 atoms that take up the entirety of the space - symmetry doesn't let me shrink the cell as far as I know)...<div><br></div><div>My question is: Should scf accuracy be going down with each iteration? I don't have much experience on large systems and I'm wondering if I'm wasting my time on this calculation(which is still ongoing). I've cherry picked a few data points below to show you my dilemma. </div><div><br></div><div>Iteration     SCF accuracy:</div><div>10th         < 10.8 Ry</div><div>20th         < 14 Ry</div><div>21st         < 618 Ry</div><div>50th         < 644 Ry</div><div>64th         < 207Ry</div><div>65th         < 469 Ry</div></div>