Physical constants (sisl.constant)

Module containing a pre-set set of physical constants.

The currently stored constants are (all are given in SI units):

PhysicalConstant	Class to create a physical constant with unit-conversion capability, works exactly like a float.
c	Speed of light [m/s]
h	Plancks constant [J s]
hbar	Reduced Plancks constant [J s]
m_e	Mass of electron [kg]
m_p	Mass of proton [kg]
G	Gravitational constant [m^3/kg/s^2]

All constants may be used like an ordinary float (which converts it to a float:

>>> c
299792458.0 m/s
>>> c * 2
599584916

while one can just as easily convert the units (which ensures thay stay like another PhysicalConstant):

>>> c('Ang/ps')
2997924.58 Ang/ps