# Module MMTK.Units

This module defines constants and prefactors that convert between MMTK's internal unit system and other units. There are also some common physical constants.

SI Prefixes: ato, femto, pico, nano, micro, milli, centi, deci, deca, hecto, kilo, mega, giga, tera, peta

Length units: m, cm, mm, nm, pm, fm, Ang, Bohr

Angle units: rad, deg

Volume units: l

Time units: s, ns, ps, fs

Frequency units: Hz, invcm (wavenumbers)

Mass units: amu, g, kg

Quantity-of-matter units: mol

Energy units: J, kJ, cal, kcal, Hartree

Temperature units: K

Pressure units: Pa, bar, atm

Electrostatic units: C, A, V, D, eV, e

Physical constants: c (speed of light), Nav (Avogadro number), h = (Planck constant), hbar = (Planck constant divided by 2*Pi), k_B = (Boltzmann constant), eps0 = (permittivity of vacuum), me = (electron mass)