Constants

This module contains useful physical constant and conversion factors

mppi.Utilities.Constants.Bohr_radius = 5.291772e-11

The Bohr radius in meter.

mppi.Utilities.Constants.Bohr_to_Angstrom = 0.529177249

Conversion factor from Bohr (the length units in a.u.) to Angstrom.

mppi.Utilities.Constants.HaToeV = 27.211386

Energy conversion factor from Hartree to eV units

mppi.Utilities.Constants.Light_speed_nm_fsm1 = 299.792458

Light speed in in nm/fs

mppi.Utilities.Constants.Planck_ev_fs = 4.135667696

Planck constant in eV*fs.

mppi.Utilities.Constants.Planck_ev_ps = 0.004135667696

Planck constant in eV*ps.

mppi.Utilities.Constants.Planck_reduced_ev_fs = 0.658211957

Reduced Planck constant (h/2pi) in eV*fs.

mppi.Utilities.Constants.Planck_reduced_ev_ps = 0.000658211957

Reduced Planck constant (h/2pi) in eV*ps.

mppi.Utilities.Constants.electron_charge = 1.60217662e-19

The charge of the electron in Coulomb

mppi.Utilities.Constants.high_sym_fcc = {'G': [0.0, 0.0, 0.0], 'K': [0.0, 1.0, 1.0], 'L': [0.5, 0.5, 0.5], 'W': [1.0, 0.5, 0.0], 'X': [0.0, 0.0, 1.0]}

High symmetry points of the fcc lattice (expressed in cartesian coordinates in units of 2pi/alat)

mppi.Utilities.Constants.high_sym_fcc_crystal = {'G': [0.0, 0.0, 0.0], 'K': [0.375, 0.75, 0.375], 'L': [0.5, 0.5, 0.5], 'W': [0.25, 0.75, 0.5], 'X': [0.0, 0.5, 0.5]}

High symmetry points of the fcc lattice (expressed in crystal coordinates)

mppi.Utilities.Constants.vacuum_impedence = 376.730313

The impedence of free space in Ohm. The field amplitude E (in V/m) is related to the field intensity P (in W/m^2) by the relation E = sqrt(Z0*P)