Other functions

List of other functions in pyqcm

exception MinimizationError
exception MissingArgError
exception OutOfBoundsError(variable)
exception ParseError
exception SolverError
exception TooManyIterationsError(max_iteration)
exception VarParamMismatchError
exception WrongArgumentError
banner(s, c='-', skip=0)

Pretty-prints a banner (one line across) on the screen with a message

Parameters:

  • s (str) – message

  • c (char) – character used in the non-text part of the banner

  • skip (int) – number of blank lines above and below the banner

class double_counting(e, V, n, coeff, e0)

Class used to correct the value of band energies and chemical potential as a function of interaction strength

\[e = e_0 + c V \langle n\rangle \]
Parameters:

  • e (str) – name of the kinetic operator to shift (e.g. a band energy)

  • V (str) – name of the interaction operator causing the shift

  • n (str) – name of the operator whose average will cause the shift

  • coeff (float) – coefficient c in the correction formula above

  • e0 (float) – bare value of the kinetic operator (before correction)

correction(I)

Applies the double counting corretion to the model instance I. Changes the parameter_set taking into account the average values within the instance I

Parameters:

I – instance of the lattice model

epsilon(y, pr=False)

Performs the epsilon algorithm for accelerated convergence (e.g. in CDMFT)

Parameters:

  • y ([float]) – sequence to be extrapolated

  • pr (boolean) – if True, prints the resulting extrapolation

Returns:

the extrapolated values

Return type:

[float]

general_interaction_matrix_elements(e, n)

Translates a list of matrix elements (i,j,k,l,v) for a general interaction into a list of compound elements (I,J,v) where I = i+n*j and J = k+n*l and v is the value of the matrix element Also checks that only non redundant elements are given. A sum over spin for the Coulomb interaction est performed.

Parameters:

  • e ((int,int,int,int,float)) – list of matrix elements

  • n (int) – number of orbitals in the impurity model (excluding spin; 2*n with spin)

get_global_parameter(name, value=None)

Gets the value of a global parameter.

Parameters:

name (str) – name of the global option

Returns:

the value, according to type

is_sequence(obj)

Tests whether an object is a sequence (list, tuple or ndarray)

orbital_manager(orbitals, from_zero=False)
orbital_pair_manager(orbitals)
print_options(opt=0)

Prints the list of global parameters on the screen

param int opt:

0 -> prints to screen. 1 -> prints to latex. 2 -> prints to RST

print_statistics()

Prints various internal statistics (number of evaluations of certains quantities, etc.)

reset_model()

Resets the lattice model. In other words, all cluster models, clusters and the content of the lattice_model object (including the parameter_set) are reset to void. Useful if one wants to conduct simulations with a new model without quitting Python.

set_global_parameter(name, value=None)

Sets the value of a global parameter. If the global parameter is Boolean, then value is True by default and should not be specified.

Parameters:

  • name (str) – name of the global option

  • value – value of that option (None, int, float or str)

Returns:

None

switch_cluster_model(name)

Switches cluster model to ‘name’. Hack used in DCA (yet to be developped)

varia_table(var, val, prefix='')

Pretty prints a list of variational parameters and values in a table form. For screen output in CDMFT and VCA

Parameters:

  • var ([str]) – list of parameter names

  • val ([float]) – list of associated values

  • prefix (str) – prefix string to each line

wavevector_grid(n=100, orig=[-1.0, -1.0], side=2, k_perp=0, plane='z')

Produces a set of wavevectors for a MDC

Parameters:

  • n (int) – number of wavevectors on the side

  • orig ([float]) – origin (in multiples of pi)

  • side (float) – length of the side (in multiples of pi)

  • k_perp (float) – momentum component in the third direction (in multiples of pi)

  • plane (str) – momentum plane, ‘xy’=’z’, ‘yz’=’x’=’zy’ or ‘xz’=’zx’=’y’

Returns:

ndarray of wavevectors (n*n x 3)

wavevector_path(n=32, shape='triangle')

Builds a wavevector path and associated tick marks

Parameters:

  • n (int) – number of wavevectors per segment

  • shape (str) – the geometry of the path, one of: line, halfline, triangle, diagonal, graphene, graphene2, tri, cubic, cubic2, tetragonal, tetragonal2 OR a tuple with two wavevectors for a straight path between the two OR a filename ending with “.tsv”. In the latter case, the file contains a tab-separated list of wavevectors (in units of pi) and tick marks: the first three columns are the x,y,z components of the wavevectors, and the last columns the strings (possibly latex) for the tick marks (write - in that column if you do not want a tick mark for a specific wavevector).

Returns tuple:

  1. a ndarray of wavevectors 2) a list of tick positions 3) a list of tick strings