electron rest mass

The electron rest mass, however, is calculated from other measured constants:

The electron rest mass (symbol: m) is the mass of a stationary electron.

The electron rest mass in kilograms is calculated from the definition of the Rydberg constant R:

There is an arbitrariness in the choice of which particle's mass to use (whereas is a function of the elementary charge, is normally a function of the electron rest mass).

That just leaves one fundamental dimension and one fundamental unit, but we still have plenty of fundamental constants left to eliminate that too - for instance one could use G, the gravitational constant, or m(e), the electron rest mass.

In a solid, the scaling of and the wavefunction size are orders of magnitude different from the hydrogen problem because the relative permittivity is roughly ten and the reduced mass in a solid is much smaller than the electron rest mass , i.e., .

The electron relative atomic mass is an adjusted parameter in the CODATA set of fundamental physical constants, while the electron rest mass in kilograms is calculated from the values of the Planck constant, the fine structure constant and the Rydberg constant.