Phonon density of states (partial and weighted):ΒΆ

The script make_TDS_intensityVolumeOnlyHisto calculates partial and x-ray or neutron weighted phonon densities of states.

  • it requires that you have previously done the following operations :

    • symmetrisation
    • Fourier transform
    • Debye waller calculation for the temperature of choice

  • The usage is

    make_TDS_IntensityVolumeOnlyHisto castep_filename input_filename

    the file castep_filename can be either the name of the original castep output or the associated hdf5 file.In any case the associated hdf5 file must exist already (make_TDS_Simmetrization must be runned beforehand)

  • The input_file must set the variables :

    • Mandatories

      • APPLYTIMEREVERSAL
      • subN1
      • subN2
      • subN3
      • N1
      • N2
      • N3
      • Nfour_interp
      • Temperature

    • If NEUTRONCALC==0 ( default )

      • Lambda

    • If NEUTRONCALC==1

      • CohB
      • NeutronE

    • Nbins

    • MAX_W

    • xvdos

    • DOQLIMITS

      • QMIN=0
      • QMAX=0

    • The following block of three parameters are either all None (default), or outputname must be set together with one of branchWeight and energyWindow

      • outputname
      • branchWeight
      • energyWindow

    • set RemoveBose=0 if you want to remove Bose statistics factors

The input variables are documented with docstrings below

make_TDS_IntensityVolumeOnlyHisto.APPLYTIMEREVERSAL = 1

this is one by default. Must be coherent with previous steps

make_TDS_IntensityVolumeOnlyHisto.subN1 = 20

Subdivision, in the elementary brillouin zone, along the Z dimension of the reconstructed volume, which is parallel to the first axis of the brilloin zone.

make_TDS_IntensityVolumeOnlyHisto.subN2 = 20

Subdivision, in the elementary brillouin zone, along the Y dimension of the reconstructed volume, which is parallel to the second axis of the brilloin zone.

make_TDS_IntensityVolumeOnlyHisto.subN3 = 20

Subdivision, in the elementary brillouin zone, along the X dimension of the reconstructed volume, which is parallel to the third axis of the brilloin zone.

make_TDS_IntensityVolumeOnlyHisto.N1 = 4

Besides being subdivised, the Brillouin zone, is replicated alonx the first axis for -N1 up to N1-1 included. In reciprocal cell vector units. N1 can be either an integer or a pair of integer. In the latter case the first element is the starting shift, the second is the ending shift+1.

make_TDS_IntensityVolumeOnlyHisto.N2 = 4

same thing as N1 but along the second reciprocal cell vector

make_TDS_IntensityVolumeOnlyHisto.N3 = 4

same thing as N1 but along the third reciprocal cell vector

make_TDS_IntensityVolumeOnlyHisto.Nfour_interp = 5

The number of points in each direction of the 3D reciprocal grid. The hdf5 file must contain a previous pretreatement done with the same parameter.

make_TDS_IntensityVolumeOnlyHisto.Temperature = 100

The hdf5 file must include DW factors calculated ALSO at this temperature. The temperature at which DW factors have been calculated. The calculation of partial DOS doesn not involve DW factors but they must be present for the script to run. Units are Kelvin

make_TDS_IntensityVolumeOnlyHisto.NEUTRONCALC = 0

This activate neutron scattering calculations.

make_TDS_IntensityVolumeOnlyHisto.Lambda = 0.2

For X-ray scattering : the wavelenght in Angstroems.

make_TDS_IntensityVolumeOnlyHisto.NEUTRONCALC = 0

This activate neutron scattering calculations.

make_TDS_IntensityVolumeOnlyHisto.CohB = None

When neutroncalc is on, this must be a dictionary : for each atom name the Coherent lenght.

make_TDS_IntensityVolumeOnlyHisto.NeutronE = 0

When neutroncalc is on, the neutron energy in meV

make_TDS_IntensityVolumeOnlyHisto.Nbins = 0

Numer of bins in the histogram

make_TDS_IntensityVolumeOnlyHisto.MAX_W = 0

The histogram spans the range [0, MAX_W]. Units are cm-1.

make_TDS_IntensityVolumeOnlyHisto.xvdos = 0
when this option is on, the DOS is calculated with a weight given by scattering factors, structure factor, DW etc. etc.
almost the same as the one used for scattering but without bose statistics.
make_TDS_IntensityVolumeOnlyHisto.DOQLIMITS = 0

If on : when calculating xvdos only contributions from q points having modulus inside a given window are considered.

make_TDS_IntensityVolumeOnlyHisto.QMIN = 0

the minimum Q modulus for the DOQLIMITS=1 window

make_TDS_IntensityVolumeOnlyHisto.QMAX = 0

the maximum Q modulus for the DOQLIMITS=1 window

make_TDS_IntensityVolumeOnlyHisto.outputname = None

a name to design the output file with data from calculation considering branchWeight or energyWindow

make_TDS_IntensityVolumeOnlyHisto.branchWeight = None

a list of weights : one per branch.

make_TDS_IntensityVolumeOnlyHisto.energyWindow = None

a list of two numbers : minimum and maximum in meV

make_TDS_IntensityVolumeOnlyHisto.RemoveBose = 0

RemoveBose=0 desactivates the Bose statistics.