Groundstate energy wrong with frozencore?
Dear exciting team,
I am working on MoS2 with spin-orbit coupling (SOC) in GGA_PBE. When I do a volume optimization with just SOC, I get a reasonable equilibrium lattice constant. When I do the same but freeze the core electrons (frozencore="true") my energy-vs-volume curve does not exhibit a minimum. Apart from minor changes in the energies of the lowest lying bands, the bandstructure looks identical.
Could you maybe explain this behaviour? Does something go wrong in the GS calculation?
Thanks in advance,
Valerie