Internal units

Jumos uses a set of internal units, converting back and forth to these units when needed. Conversion from SI units is always supported. Parenthesis indicate planned conversion that is not implemented yet.

Quantity	Internal unit	Supported conversions
Distances	Ångtröm (\(A\))	(bohr)
Time	Femptosecond (\(fs\))
Velocities	Ångtröm/Femptosecond (\(A/fs\))
Mass	Unified atomic mass (\(u\) or \(Da\))	\(g/mol\)
Temperature	Kelvin (\(K\))
Energy	Kilo-Joule/Mole (\(kJ/mol\))	(\(eV\)), (\(Ry\)), (\(kcal/mol\))
Force	Kilo-Joule/(Mole-Ångtröm) \(kJ/(mol A)\)
Pressure	\(bar\)	(\(atm\))
Charge	Multiples of \(e = 1.602176487\ 10^{-19}C\)

Interaction with others units systems

Jumos uses it’s own unit system, and do not track the units in the code. All the interaction with units is based on the SIUnits package. We can convert from and to internal representation using the following functions :

internal(value::SIQuantity)

Converts a value with unit to its internal representation.

julia> internal(2m)         # Distance
    1.9999999999999996e10

julia> internal(3kg*m/s^2)  # Force
    7.17017208413002e-14

with_unit(value::Number, target_unit::SIUnit)

Converts an internal value to its value in the International System. You shall note that units are not tracked in the code, so you can convert a position to a pressure. And all the results are returned in the main SI unit, without considering any power-of-ten prefix.

This may leads to strange results like:

julia> with_unit(45, mJ)
    188280.0 kg m²/s²

julia> with_unit(45, J)
    188280.0 kg m²/s²

This behaviour will be corrected in future versions.