Units of Measure¶
Atomic Units¶
- \(\mathrm B\) – Bohr radius, atomic unit of length, equal to \(0.52917721067\ \mathring{\mathrm A}\) or \(0.52917721067\times 10^{-10}\ \mathrm m\) – [NISTCUU_B]
- \(\mathrm{E_h}\) – Hartree, atomic unit of energy, equal to \(4.35974465~\mathrm J\) – [NISTCUU_Eh]
- \(\mathrm{m_e}\) – Electron mass, atomic unit of mass, equal to \(9.10938356\times 10^{-31} \ \mathrm{kg}\) – [NISTCUU_me]
- \(\mathrm{T_a}\) – Atomic time unit, equal to \(2.4188843265\times 10^{-17}\ \mathrm s\) – [NISTCUU_Ta]
Other Units¶
- \(\mathrm{cyc}\) – Numerical value of \(2\pi\ \left(\frac{\mathrm{cyc}}{2\pi}=1\right)\), serving to convert angular frequencies into cyclic frequencies.
- \(\mathrm{u}\) – unified atomic mass unit; equal to \(1822.8885\ \mathrm{m_e}\) [NISTCUU_me_u] or \(1.660539040\times 10^{-27}\ \mathrm{kg}\) [NISTCUU_u_kg].