Examples#

The examples folder contains a plethora of self-contained examples to get started with running (and processing the results of) EXCEED-DM. Each folder contains its own:

  • readme.md: explaining in words what calculation is doing. Repeated below for convenience.

  • input.txt: input file. This is where the run parameters (dark matter masses, velocity distribution, etc.) are defined.

  • elec_config.hdf5: electronic configuration file. This contains all the information about the electronic states used in the calculation. For example, in example 1 only the valence and conduction bands in Si are included. Other examples will include more, or other, states.

  • analysis.ipynb: analysis Jupyter notebook, to study the output in more detail.

  • output folder, where the EXCEED-DM output file, EXDM_out_example_<#>.hdf5, is stored.

Running#

  • To perform an example calculation, go to the main folder and run,

      mpirun -np <n_proc> ./build/exdm ./examples/<example_ID>/input.txt

where <n_proc> is the number of processors to run on and <example_ID> is the example ID you want to compute for.

  • To run all the examples, from the main folder run,

      ./examples/run_all_examples.sh <n_proc>

where <n_proc> is the number of processors to run on.

Warning

Running all of the examples takes ~5 minutes on 48 cores.

Descriptions#

Example 1: Si Binned Scatter Rate, valence to conduction#

  • Calculation: Binned scatter rate

  • Target: Si

Valence to conduction transitions in Si using an example \(2 \times 2 \times 2\) \(\mathbf{k}\)-mesh. Useful for timing this section of the whole calculation.

Example 2: Si Binned Scatter Rate, core to conduction#

  • Calculation: Binned scatter rate

  • Target: Si

Core to conduction transitions in Si. Core states are RHF wave functions with \(1 \leq n \leq 2\) in an STO basis. Conduction states are the same as in example 1; PW basis wave functions on a \(2 \times 2 \times 2\) \(\mathbf{k}\)-mesh.

Example 3: Si Binned Scatter Rate, valence to free#

  • Calculation: Binned scatter rate

  • Target: Si

Valence to free transitions in Si. Valence states are identical to example 1; PW basis on a \(2 \times 2 \times 2\) \(\mathbf{k}\)-mesh. Free states have \(p\) log-uniformly sampled on a 10 point grid between [60, 120] \(\mathrm{eV}\), and \(\theta_\mathbf{p}, \phi_\mathbf{p}\) uniformly sampled on a sphere with \(4 \times 4\) points.

Additionally we assume \(Z_\mathrm{eff} = 1\).

Example 4: Si Binned Scatter Rate, core to free#

  • Calculation: Binned scatter rate

  • Target: Si

Core to free transitions in Si. Core states are identical to example 2; STO basis for \(1 \leq n \leq 2\). Free states are identical to example 3; \(p\) log-uniformly sampled on a 10 point grid between [60, 120] \(\mathrm{eV}\), and \(\theta_\mathbf{p}, \phi_\mathbf{p}\) uniformly sampled on a sphere with \(4 \times 4\) points.

Additionally we assume \(Z_\mathrm{eff} = 1\).

Example 5: Si Binned Scatter Rate, All Transitions Included#

  • Calculation: Binned scatter rate

  • Target: Si

Complete calculation of transition rates in Si. Initial electronic states are a combination of the valence and core states from examples 1 and 2. Final electronic states are a combination of the conduction and free states from examples 2 and 3. See those example readme’s for more details.

Example 6: Si Axion Absorption Rate, valence to conduction#

  • Calculation: Absorption rate

  • Target: Si

Absorption rate of an axion-like particle, for two \(\delta\): \(\delta = 1 \, \mathrm{eV}\) and \(\delta = 0.2 + 10^{-1} \omega\). Only valence to conduction transitions are included.

Note

This electronic state configuration is identical to Example 1.

Example 7: Si Axion Absorption Rate, core to conduction#

  • Calculation: Absorption rate

  • Target: Si

Absorption rate of an axion-like particle, for two \(\delta\): \(\delta = 1 \, \mathrm{eV}\) and \(\delta = 0.2 + 10^{-1} \omega\). Only core to conduction transitions are included.

Example 8: Si Axion Absorption Rate, valence to free#

  • Calculation: Absorption rate

  • Target: Si

Absorption rate of an axion-like particle, for two \(\delta\): \(\delta = 1 \, \mathrm{eV}\) and \(\delta = 0.2 + 10^{-1} \omega\). Only valence to free transitions are included.

Example 9: Si Axion Absorption Rate, core to free#

  • Calculation: Absorption rate

  • Target: Si

Absorption rate of an axion-like particle, for two \(\delta\): \(\delta = 1 \, \mathrm{eV}\) and \(\delta = 0.2 + 10^{-1} \omega\). Only core to free transitions are included.

Example 10: Si Axion Absorption Rate, All Transitions Included#

  • Calculation: Absorption rate

  • Target: Si

Absorption rate of an axion-like particle, for two \(\delta\): \(\delta = 1 \, \mathrm{eV}\) and \(\delta = 0.2 + 10^{-1} \omega\).

Example 11: Si Dielectric#

  • Calculation: Dielectric

  • Target: Si

Compute the (averaged) dielectric, \(\bar{\varepsilon}(\mathbf{q}, \omega)\), of Si.

Note

This electronic configuration is the same as Example 5.

Warning

The transition form factors used in this calculation are not in the \(q \rightarrow 0\) limit. This is appropriate for screening scattering rate calculations, but not for absorption calculations which, sometimes, may be written in terms of the long wavelength dielectric, \(\varepsilon(\mathbf{q} \rightarrow 0, \omega)\).

Example 12: Si (Analytic) Screened Binned Scatter Rate, All Transitions Included#

  • Calculation: Binned scatter rate

  • Target: Si

Complete calculation of transition rates in Si with an analytic model used for the screening factor.

Note

The electronic configuration used here is identical to Example 5.

Example 13: Si (Numeric) Screened Binned Scatter Rate, All Transitions Included#

  • Calculation: Binned scatter rate

  • Target: Si

Complete calculation of transition rates in Si with the numerically computed dielectric (Example 11) used for the screening factor.

Note

The electronic configuration used here is identical to Example 5.

Example 14: Si Binned Scatter Rate, valence to conduction#

  • Calculation: Binned scatter rate

  • Target: Si

Valence to conduction transitions in Si using an example \(2 \times 2 \times 2\) \(\mathbf{k}\)-mesh. Wave function coefficients have been doubled to produce artifical “spin dependent” wave functions. Scattering rate is determined by the ‘SD’ operator and the results will be idential to Example 1 (by construction). Useful for timing this section of the whole calculation.

Example 15: Si Binned Scatter Rate, V-A model#

  • Calculation: Binned scatter rate

  • Target: Si

Calculation of the binned scatter rate in Si with a model containing \(\mathbf{v}_e\) dependent scattering potential.

Note

The electronic configuration used here is identical to Example 5.

Example 16: Absorption Rate, Xe target#

  • Calculation: Absorption rate

  • Target: Xe

Atomic STO basis -> atomic continuum transitions in Xe.

Example 17: Si Absorption Rate, EDM model#

  • Calculation: Absorption

  • Target: Si

Calculation of the absorption rate in Si for the EDM model.

Note

The electronic configuration used here is identical to Example 10.