<div>hello, everyone.</div>
<div> These days, I performed the convergence of scf calculation with some USPP, but never see a good ecut convergence. The system only contains 3 atoms, with 12x12x12 kpoints automatic generated in MP grids.</div>
<div> Why does the press differ each so mush? Is 200ev Ry too high for USPP? And which press is more convictional?</div>
<div> Can anyone give me some suggestion? Thanks in advance.</div>
<div> ecut=80 :<br>! total energy = -61.89999202 Ry<br> total stress (Ry/bohr**3) (kbar) P= 0.59<br> ecut=100 :<br>! total energy = -61.90651146 Ry
<br> total stress (Ry/bohr**3) (kbar) P= -5.39<br> ecut=140 :<br>! total energy = -61.90331161 Ry<br> total stress (Ry/bo hr**3) (kbar) P=
0.97<br> ecut=180 :<br>! total energy = -61.90482904 Ry<br> total stress (Ry/bohr**3) (kbar) P= 10.64<br> ecut=200 :<br>! total energy = -61.90542701
Ry<br> total stress (Ry/bohr**3) (kbar) P= -4.55<br> ecut=240 :<br>! total energy = -61.90875043 Ry<br> total stress (Ry/bohr**3) (kbar) P=
5.92<br> ecut=280 :<br>! total energy = -61.90854533 Ry<br> total stress (Ry/bohr**3) (kbar) P= 1.68<br> </div>