atoms shifted ? question about CHGCAR

[nus11]

Hello, everyone
I was reading the CHGCAR file and plot the contourplot of the charge density.Because of the symmetry,the charge desity is centered around atoms. however, I found that the atoms are somehow shifted in one direction. For example, when I look at the fractional positions of one atom in CHGCAR file, it is close to the origin, however, in the contourplot plotted using data from CHGCAR file, that atom is shifted in x direction by some amount.(not negligible)

what might be the problem?
My idea is there are two setups, one is the location of atoms and another is the mesh nx*ny*nz in the CHGCAR file, how are these two related?

thanks a lot

[admin]

there are two sources of misinterpretation:
1) the data in CHGCAR are written as
(((CHG(nx,ny,nz),nx=1,ngx),ny=1,ngy), nz=1,ngz)
2) transform the positions written in CONTCAR back to positions in
carthesian coordinates (or, alternatively have a look in OUTCAR) .