ühikute süsteem, kus põhiühikuteks on elementaarlaeng, elektroni mass, taandatud Plancki konstant, Bohri raadius ja Hartree energia ning tuletatud ühikuks on aeg, system of units in which the basic units are the elementary charge, the electron mass, the reduced Planck constant, the Bohr radius, and the Hartree energy, and the derived unit is time
