<html><head></head><body><div class="yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div dir="ltr" data-setdir="false">Dear all</div><div dir="ltr" data-setdir="false">I'm trying to study the effect of monolayer coverage (ML) on adsorption energy for Sulfur on Ni2P surface (2x2x2). The complex system ( one S adatom +slab) (ML=0.25) does converge well , however after increasing the coverage to ML=0.5 (two sulfur adatoms + slab), the system doesn't converge at all. Can you explain why the system doesn't converge after placing another sulfur adatom ?</div><div dir="ltr" data-setdir="false"> Attached is my input file</div><div dir="ltr" data-setdir="false">Regards</div></div></body></html>