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I have one problem to calculate the free atom energy without magnetism for tungsten. I just find the
electronic relaxation can reach 60 steps(which is the default value for NELM) and stop. If I set NELM larger, it
can run NELM steps. However, does this mean that the relaxation process converges or how can we get convergence.

I also decreased SIGMA and it still ran NELM steps.

Thanks a lot. The files are listed below:
INCAR:
System = W, single atom
ENCUT = 330
ISMEAR = 0
SIGMA = 0.1
EDIFF=0.0001
ISPIN=1
NELM=120
POSCAR:
W in single atom
25
1 0 0
0 1 0
0 0 1
1
direct
0.0 0.0 0.0
KPOINTS:
automatic_generate
0
Monkhorst
1 1 1
0 0 0

Part of the OSIZCAR:
RMM: 117 -0.187057037789E+01 0.18275E+00 -0.42782E-02 14 0.209E+00 0.576E+00
RMM: 118 -0.205330092095E+01 -0.18273E+00 -0.26786E-02 14 0.158E+00 0.521E+00
RMM: 119 -0.187051176102E+01 0.18279E+00 -0.42779E-02 14 0.209E+00 0.576E+00
RMM: 120 -0.205331395580E+01 -0.18280E+00 -0.26784E-02 14 0.158E+00
1 F= -.20533140E+01 E0= -.20318639E+01 d E =-.643501E-01

Try to set SIGMA to zero. I find this often helps to improve convergence for single atoms.

1) please mind that for free atoms Hund's rule applies!
2) SIGMA gas to be chosen much smaller for free atoms (discrete levels),
set it to 0.001 or even less