# DoubleContourIntegralParameters¶

DoubleContourIntegralParameters(integral_lower_bound=None, circle_eccentricity=None, logarithmic_bunching=None, circle_points=None, real_axis_point_density=None, real_axis_infinitesimal=None, real_axis_kbt_padding_factor=None, fermi_line_points=None, fermi_function_poles=None)

Representation of the contour parameters when using a double contour.

Deprecated since version 2016.0: Use ContourParameters instead.

Parameters: integral_lower_bound (PhysicalQuantity of type energy) – The distance between the lowest Fermi-level to the lowest energy circle contour point. Default: 1.5 * Hartree circle_eccentricity (float) – The eccentricity of the circle contour. This should be a float between 0 and 1. 0 is a circle, 1 is a line. Default: 0.3 logarithmic_bunching (float) – Logarithmic bunching of the circle contour around the Fermi level. This should be a float between 0 and 1. 0 means no bunching, equidistant points, 1 means all bunched, centred on the Fermi Level. Default: 0.3 circle_points (int) – The number of points on the circle contour. Must be at least 3. Default: 30 real_axis_point_density (PhysicalQuantity of type energy) – Spacing between the points on bias window integration line close to the real axis. Default: 0.001 * Hartree real_axis_infinitesimal (PhysicalQuantity of type energy) – Small imaginary shift of the bias window integration line from the real axis. Default: 0.001 * Hartree real_axis_kbt_padding_factor (float) – The integration line is extended with the amount $$f k_b T$$ below and above the electrode Fermi levels where $$f$$ is this value. Must be larger than 0.0. Default: 5.0 fermi_line_points (int) – The number of points on the straight line from the Fermi energy level up to infinity. This should be an integer in the range 1 to 11 (inclusive). Default: 10 fermi_function_poles (int) – The number of poles of the Fermi function to include. Determines the imaginary shift of the straight line from the Fermi level to infinity. Must be positive. Default: 8 A ContourParameters object consisting of the SemiCircleContour equilibrium contour and the RealAxisContour Non-equilibrium contour. Both left and right are set. ContourParameters

## Notes¶

This class is deprecated and only included for backwards compatibility.

A DoubleContourIntegralParameters object:

contour_parameters = DoubleContourIntegralParameters(
integral_lower_bound=5.0*Hartree,
circle_eccentricity=0.5,
logarithmic_bunching=0.4,
circle_points=30,
real_axis_point_density=0.002*eV,
real_axis_infinitesimal=1e-05*eV,
fermi_line_points=10,
fermi_function_poles=8)


is equivalent to the following ContourParameters object

eq_contour = SemiCircleContour(
integral_lower_bound=5.0*Hartree,
circle_eccentricity=0.5,
logarithmic_bunching=0.4,
circle_points=30
fermi_line_points=10,
fermi_function_poles=8)

neq_contour = RealAxisContour(
real_axis_point_density=0.002*eV,
real_axis_infinitesimal=1e-05*eV