My Community

hi ,
when I optimized structure, the calculation was interrupted.
I find the following output in the out file.

WARNING: Sub-Space-Matrix is not hermitian in DAV
5.080957515206845E-005

I copy the CONTCAR to POSCAR to continue the calculation,but it interrupted again. the warning is similar.
the INCAR was:
general:
SYSTEM = clean W(100) surface
ENCUT = 315
EDIFFG= -0.02
ISMEAR = 2 ; SIGMA = 0.2
dynamic:
IBRION = 2
NSW = 200
POTIM = 0.1

how i can eliminate the warning and calculate correctly ??


thanks

Most often, these errors are related to unreasonable ionic structures. Therefore please check if that error occured at the first ionic step (input POSCAR (and the interatomic NN distances listed in OUTCAR) ) or at some later step of the relaxation history (XDATCAR).
If the error occured at the first ionic step although the geometry input was reasonable, please check if the k-point mesh was sufficient (have you converged it properly for the bulk optimization?).
if the error occured at some later ionic step, please have a look if the error persists if you choose a different ionlc relaxation algorithm (like damped MD).