# Re: [Wannier] How to convert the unit of spin Hall conductivity from "(hbar/e)*S/cm" to "e2/h"?

```Hi Abid,

(hbar/e)*S/cm is the unit of SHC for 3D structures, e^2/h is the unit of AHC
for 2D structures. If you are calculating SHC of a 2D structure by using a
slab with vacuum, then you could first multiply the result by the thickness
along z axis (assuming z axis is the direction normal to the slab plane, i.e.
the total thickness of the slab and the vacuum), so now the unit is (hbar/
e)*S. Secondly, multiply the result by (-2e/hbar) [i.e. "convert" a spin
angular momentum (hbar/2) to a charge (-e)], now the unit is S. Since e^2/hbar
~= 2.434e-4 S, it's easy to do the reverse and you get the unit in e^2/h.```
```
Best,
Junfeng QIAO
Doctoral Assistant
EPFL THEOS
Switzerland

On Sunday, May 2, 2021 9:54:33 AM CEST Abid Rehman wrote:
> Hi all,
> As we know, The wannier90 gives Spin Hall conductivity in units of
> *(hbar/e)*S/cm.
> *I want to express the spin Hall conductivity in *e2**/h *unit. So how can
> I convert the data from  *(hbar/e)*S/cm *to* e2/h unit?*
> Thanks

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