oct-propagation_spectrum

Name PropagationSpectrumDampFactor
Section Utilities::oct-propagation_spectrum
Type float
Default -1.0

If PropagationSpectrumDampMode = exponential, gaussian, the damping parameter of the exponential is fixed through this variable. Default value ensure that the damping function adquires a 0.0001 value at the end of the propagation time.

Name PropagationSpectrumDampMode
Section Utilities::oct-propagation_spectrum
Type integer

Decides which damping/filtering is to be applied in order to calculate spectra by calculating a Fourier transform. The default is polynomial damping, except when SpectrumMethod = compressed_sensing. In that case the default is none.

Options:

• none:
  No filtering at all.
  
• exponential:
  Exponential filtering, corresponding to a Lorentzian-shaped spectrum.
  
• polynomial:
  Third-order polynomial damping.
  
• gaussian:
  Gaussian damping.
  

Name PropagationSpectrumEndTime
Section Utilities::oct-propagation_spectrum
Type float
Default -1.0 au

Processing is done for the given function in a time-window that ends at the value of this variable. If set to a negative value, the maximum value from the corresponding multipole file will used.

Name PropagationSpectrumEnergyStep
Section Utilities::oct-propagation_spectrum
Type float
Default 0.01 eV

Sampling rate for the spectrum. If you supply a number equal or smaller than zero, then the sampling rate will be $2 \pi / T$, where $T$ is the total propagation time.

Name PropagationSpectrumMaxEnergy
Section Utilities::oct-propagation_spectrum
Type float
Default 20 eV

The Fourier transform is calculated for energies smaller than this value.

Name PropagationSpectrumMinEnergy
Section Utilities::oct-propagation_spectrum
Type float
Default 0

The Fourier transform is calculated for energies larger than this value.

Name PropagationSpectrumSigmaDiagonalization
Section Utilities::oct-propagation_spectrum
Type logical
Default .false.

If PropagationSpectrumSigmaDiagonalization = yes, the polarizability tensor is diagonalizied. This variable is only used if the cross_section_tensor is computed.

Name PropagationSpectrumStartTime
Section Utilities::oct-propagation_spectrum
Type float
Default 0.0

Processing is done for the given function in a time-window that starts at the value of this variable.

Name PropagationSpectrumSymmetrizeSigma
Section Utilities::oct-propagation_spectrum
Type logical
Default .false.

The polarizablity tensor has to be real and symmetric. Due to numerical accuracy, that is not extricly conserved when computing it from different time-propations. If PropagationSpectrumSymmetrizeSigma = yes, the polarizability tensor is symmetrized before its diagonalizied. This variable is only used if the cross_section_tensor is computed.

Name PropagationSpectrumTransform
Section Utilities::oct-propagation_spectrum
Type integer
Default sine

Decides which transform to perform, if SpectrumMethod = fourier.

Options:

• sine:
  Sine transform: $\int dt \sin(wt) f(t)$. Produces the imaginary part of the polarizability.
  
• cosine:
  Cosine transform: $\int dt \cos(wt) f(t)$. Produces the real part of the polarizability.
  
• laplace:
  Real exponential transform: $\int dt e^{-wt} f(t)$. Produces the real part of the polarizability at imaginary frequencies, e.g. for Van der Waals $C_6$ coefficients. This is the only allowed choice for complex scaling.
  

Name PropagationSpectrumType
Section Utilities::oct-propagation_spectrum
Type integer
Default AbsorptionSpectrum

Type of spectrum to calculate.

Options:

• AbsorptionSpectrum:
  Photoabsorption spectrum.
  
• EnergyLossSpectrum:
  Dynamic structure factor (also known as energy-loss function or spectrum).
  
• DipolePower:
  Power spectrum of the dipole moment.
  
• RotatoryStrength:
  Rotatory strength spectrum.
  

Name SpectrumMethod
Section Utilities::oct-propagation_spectrum
Type integer
Default fourier

Decides which method is used to obtain the spectrum.

Options:

• fourier:
  The standard Fourier transform. Further specified by PropagationSpectrumTransform.
  
• compressed_sensing:
  (Experimental) Uses the compressed sensing technique.
  

Name SpectrumSignalNoise
Section Utilities::oct-propagation_spectrum
Type float
Default 0.0

For compressed sensing, the signal to process, the time-dependent dipole in this case, is assumed to have some noise that is given by this dimensionless quantity.

Name TransientAbsorptionReference
Section Utilities::oct-propagation_spectrum
Type string
Default “."

In case of delayed kick, the calculation of the transient absorption requires to substract a reference calculation, containing the gauge-field without the kick This reference must be computed using GaugeFieldPropagate=yes and to have TDOutput = gauge_field. This variables defined the directory in which the reference gauge_field field is, relative to the current folder