Density of state and related tools

The Density of state: DOS

class triqs.dos.DOS(eps, rho, name='')

• Stores a density of state of fermions

\[\rho (\epsilon) \equiv \sum'_k \delta( \epsilon - \epsilon_k)\]

• The sum is normalized

\[\int_{-\infty}^{\infty} d\epsilon \rho (\epsilon) = 1\]

• Implement Plot Protocol.

copy()

density(mu=0)

Calculates the density of free fermions for the given DOS for chemical potential mu.

Reading a DOS from a text file

triqs.dos.dos_from_file(Filename, name='', single_orbital=None)

Read the DOS from a file

Parameters:

• Filename – a string : name of the file
• name – name of the DOS
• single_orbital – can be None or an integer.

Return type:

• if single_orbital== None, returns a tuple of DOS (even if there is one dos !).
• If single_orbital==i, return only ONE DOS corresponding to ith orbital (starting at 1).

Format of the file :

• N_orbitals +1 columns,
• the first column is the value of epsilon
• the N_orbitals other columns are the values of the dos for various orbitals

Computing a DOS from a tight_binding

triqs.lattice.tight_binding.dos(tight_binding, n_kpts, n_eps, name)

Parameters:

• tight_binding – a tight_binding object
• n_kpts – the number of k points to use in each dimension
• n_eps – number of points used in the binning of the energy
• name – name of the resulting dos

Return type:

return a list of DOS, one for each band

The DOS computed from a function

class triqs.dos.DOSFromFunction(function, x_min, x_max, n_pts=100, name='')

• A DOS class, but constructed from a function.
• The number of points can be variable and self-adjusted in the Hilbert transform to adapt precision.