sisl.constant
A pre-set set of physical constants. The SI units are following the new convention that takes effect on 20 May 2019.
The currently stored constants are (all are given in SI units):
PhysicalConstant q c h hbar m_e m_p G0 G
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