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Problem in optimization

Posted: Fri Nov 30, 2007 3:12 am
by weizz
hi, anyone
When I optimize the structure of Rh(110), the following message is found in OUTCAR file,

" WARNING: Sub-Space-Matrix is not hermitian in DAV 1"

The INCAR used in calculation is :
general:
SYSTEM = clean Rh(110) surface
ENCUT = 315
EDIFFG=-0.02
ISMEAR = 2 ; SIGMA = 0.2
dynamic:
IBRION = 2
NSW = 200
POTIM = 0.1
LREAL =A


I want to know whether this affect the accuracy of final results? if yes, how I can resolve the problem???

Problem in optimization

Posted: Fri Nov 30, 2007 9:25 am
by admin
usually this error occurs if the ionic configuration of this step is not reasonable, therefore please check at which ionic step this error occurs:
1) if at the first ionic step: please check your POSCAR (and the inter-atomic distances as given in OUTCAR)
2) if at some later step: please check (in XDATCAR or OUTCAR) if the system has relaxed into an unreasonable geometry (if so, use a different relaxation algorthm. POTIM seems reasonable.)