Default values (snompy.defaults)#
A class holding default values used by various functions in
snompy.
Sample-related#
- eps_envcomplex, default 1 + 0j
Dielectric function of the environment
Tip-related#
- z_tipfloat, default 0
Height of the tip above the sample.
- r_tipfloat, default 20e-9
Radius of curvature of the AFM tip.
- L_tipfloat, default 300e-9
Semi-major axis length of the effective spheroid from the finite dipole model.
Finite dipole model-related#
- g_factorcomplex, default 0.7 * np.exp(0.06j)
A dimensionless approximation relating the magnitude of charge induced in the AFM tip to the magnitude of the nearby charge which induced it. A small imaginary component can be used to account for phase shifts caused by the capacitive interaction of the tip and sample.
- d_Q0float, default 1.31 * L_tip / (L_tip + 2 * r_tip))
Depth of an induced charge 0 within the tip. Specified in units of the tip radius.
Note
When not specified by the user, the default for d_Q0 is calculated from r_tip and L_tip at execution time. There is therefore no value snompy.defaults.d_Q0.
- d_Q1float, default 0.5
Depth of an induced charge 1 within the tip. Specified in units of the tip radius.
- d_Qafloat, default 1.4
Depth of a single representative charge within the tip. Specified in units of the tip radius. Used by the “Q_ave” implementation of the finite dipole model to calculate the effective quasistatic reflection coefficient for the tip.
Demodulation-related#
- n_trapzint, default 32
The number of intervals to use for the trapezium-method integration used by snompy.demodulate.demod.
Momentum integral-related#
- n_lagint, default 32
The order of the Laguerre polynomial approximation used for integrating exponentially-weighted, semi-definite integrals.
Taylor inversion-related#
- n_taylint, default 16
Order of the Taylor approximation to the effective polarizability.
- beta_thresholdfloat
The maximum amplitude of returned beta values determined to be valid when inverting the Taylor approximation for the effective polarizability.