# [Wien] [wien2wannier] unit of |w(r)|^2 in case.xsf and case.psink

```Dear wien2wannier developers/users,

I am using wien2wannier to generate and plot the wannier orbitals of an Fe
compound. The wannier functions plotted in XCrySDen look reasonable and
have the correct shape/symmetry of d orbitals.```
```
Then I want to check the normalization of the wannier function, so I
integrate the grid and assume the unit of |w(r)|^2 to be 1/A^3, as the unit
parameter set in my case.inwplot file. But the number turns to be ~450, too
much larger than the expected 1.

Please see below the case.inwplot I used. The length of grid axes is twice
of the lattice vectors, and the number of mesh points is 100x100x100.

I understand that the density of mesh points could have an effect on the
precision of numerical integration, but I would not expect such a huge
difference... Maybe I am wrong... For now I think more likely I am using a
wrong unit of the density. But I didn't find this information from the
wien2wannier userguide. I would appreciate it if you can give any advice or
suggestion on this issue. Thank you very much!

Best,
Wenhu Xu

========================================================================

3D ORTHO        # mode O(RTHOGONAL)|N(ON-ORTHOGONAL)

-176 -126 -147 100      #x, y, z, divisor of orig

24 -126 -147 100      #x, y, z, divisor of x-end

-176 74 -147 100      #x, y, z, divisor of y-end

-176 -126 53 100      #x, y, z, divisor of z-end

100 100 100  0 0 0 # grid points and echo increments

NO              # DEP(HASING)|NO (POST-PROCESSING)

WAN ANG LARGE   # switch ANG|ATU|AU LARGE|SMALL

1  1            # k-point, Wannier index

========================================================================
```
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```
• [Wien] [wien2wannier] unit of |w(r)|^2 in case.xsf and case.... Xu Wenhu