Quickstart

For example, to determine the symmetry of the conductivity tensor effect of bcc Fe you need an input file that specifies its crystal structure:

Fe
0.001
2
3 3 3 90 90 90
2
I
1
Fe
magnetic
0 0 0 0 0 1

Save this as Fe.in. The input file format is described in detail here.

symmetr res j E -f Fe.in

This specifies that we want the response tensor corresponding to the current induced by electric field, i.e. the conductivity tensor.

This returns:

even part of the response tensor:
⎡x₀₀   0    0 ⎤
⎢             ⎥
⎢ 0   x₀₀   0 ⎥
⎢             ⎥
⎣ 0    0   x₂₂⎦
odd part of the response tensor:
⎡ 0   -x₁₀  0⎤
⎢            ⎥
⎢x₁₀   0    0⎥
⎢            ⎥
⎣ 0    0    0⎦

Here the even part refers to the T-even part of the conductivity tensor, which is the normal conductivity. The T-odd part refers to the anomalous Hall effect.

The \(x_{ij}\) variables are independent components of the tensor.

If we are instead interested in the current due to a thermal gradient, we specify:

symmetr res j gT -f Fe.in

The output in this case is the same.

The observable types are described in detail here.

Examples

Examples of using the code can be found in the examples directory within the GitHub repository.