optmat.constants

Physical constants and unit conversions, SI throughout.

Thin, named wrappers over scipy.constants (CODATA) so that no module spells a constant by hand, plus the atomic-unit conversions the polarizability data need. The historical pressure units (atmosphere, torr) and the named reference temperatures are here too, because the literature reduces its measurements to states written in them.

Module Attributes

C	Speed of light in vacuum, m/s.
EPS0	Vacuum permittivity, F/m.
HBAR	Reduced Planck constant, J s.
E_CHARGE	Elementary charge, C.
M_E	Electron mass, kg.
K_B	Boltzmann constant, J/K.
N_A	Avogadro constant, 1/mol.
ATOMIC_MASS	Atomic mass constant (unified atomic mass unit), kg.
BOHR_RADIUS	Bohr radius a0, m.
CLASSICAL_ELECTRON_RADIUS	Classical electron radius r_e = e^2 / (4 pi eps0 m_e c^2), m.
AU_ENERGY	Hartree energy, J: the atomic unit of energy.
AU_ANGULAR_FREQUENCY	Atomic unit of angular frequency, rad/s (one hartree divided by hbar).
AU_POLARIZABILITY	Atomic unit of dipole polarizability, C m^2/V.
AU_FIELD	Atomic unit of electric field, V/m (E_h / (e a0), 5.14e11 V/m).
STD_ATMOSPHERE	Standard atmosphere, Pa (101 325 exactly).
BAR	Bar, Pa (100 000 exactly).
TORR	Torr (mm of mercury in the older literature, to the precision that matters), Pa.
ZERO_CELSIUS	The ice point, 273.15 K.

optmat.constants.ATOMIC_MASS: float = 1.66053906892e-27

Atomic mass constant (unified atomic mass unit), kg.

optmat.constants.AU_ANGULAR_FREQUENCY: float = 4.134137333517135e+16

Atomic unit of angular frequency, rad/s (one hartree divided by hbar).

optmat.constants.AU_ENERGY: float = 4.359744722206e-18

Hartree energy, J: the atomic unit of energy.

optmat.constants.AU_FIELD: float = 514220675111.98303

Atomic unit of electric field, V/m (E_h / (e a0), 5.14e11 V/m).

optmat.constants.AU_POLARIZABILITY: float = 1.6487772721219234e-41

Atomic unit of dipole polarizability, C m^2/V.

An atomic-unit polarizability alpha_au (in units of a0^3 in the Gaussian sense) is alpha_au * AU_POLARIZABILITY in SI.

optmat.constants.BAR: float = 100000.0

Bar, Pa (100 000 exactly).

optmat.constants.BOHR_RADIUS: float = 5.29177210544e-11

Bohr radius a0, m.

optmat.constants.C: float = 299792458.0

Speed of light in vacuum, m/s.

optmat.constants.CLASSICAL_ELECTRON_RADIUS: float = 2.8179403205e-15

Classical electron radius r_e = e^2 / (4 pi eps0 m_e c^2), m.

optmat.constants.EPS0: float = 8.8541878188e-12

Vacuum permittivity, F/m.

optmat.constants.E_CHARGE: float = 1.602176634e-19

Elementary charge, C.

optmat.constants.HBAR: float = 1.0545718176461565e-34

Reduced Planck constant, J s.

optmat.constants.K_B: float = 1.380649e-23

Boltzmann constant, J/K.

optmat.constants.M_E: float = 9.1093837139e-31

Electron mass, kg.

optmat.constants.N_A: float = 6.02214076e+23

Avogadro constant, 1/mol.

optmat.constants.STD_ATMOSPHERE: float = 101325.0

Standard atmosphere, Pa (101 325 exactly).

optmat.constants.TORR: float = 133.32236842105263

Torr (mm of mercury in the older literature, to the precision that matters), Pa.

optmat.constants.ZERO_CELSIUS: float = 273.15

The ice point, 273.15 K.