Energy E		J nJ eV meV μeV neV
Frequency E = hf		Hz kHz MHz GHz THz
Period E = h/T		s ms μs ns
Wavelength E = hc/λ		m mm um nm
Wavenumber E = ħck		m-1 cm-1 mm-1
Magnetic field E = g μ_B B (g=2)		T mT gauss mgauss
Temperature E = k_B T		K mK