Hello!
I'am junior in exciting group. I try to understend rgkmax - convergence of ferromagnetic bcc Fe system. Difference between total energy with (rkmax = 8, ngridk = 12 12 12) and (rkmax = 9, ngridk = 12 12 12) is 0.08 eV/atom. What total energy threshold (eV/atom) of rgmax to use for bulk calculations?
<input>
<title>Paramagnetic Fe-bcc</title>
<structure speciespath="$EXCITINGROOT/species">
<crystal scale="5.20">
<basevect> 0.5 0.5 -0.5</basevect>
<basevect> 0.5 -0.5 0.5</basevect>
<basevect>-0.5 0.5 0.5</basevect>
</crystal>
<species speciesfile="Fe.xml" rmt="2.0" bfcmt="0.0 0.0 -2.0">
<atom coord="0.0 0.0 0.0"/>
</species>
</structure>
<groundstate
xctype="GGA_PBE"
rgkmax="8.0"
ngridk="12 12 12"
stype="Gaussian"
swidth="0.01"
nempty="10">
<spin>
</spin>
</groundstate>
</input>
Cheerio!