<Li> Stoney units are similar to Planck units but set the elementary charge to unity and allow Planck's constant to float (i.e. it is a number that has to be determined by experiment). </Li> <Li> "Schrödinger" units are also similar to Planck units and also set the elementary charge to unity, but allow the speed of light to float . </Li> <Li> Atomic units are a system of units used in atomic physics, particularly for describing the properties of electrons . The atomic units have been chosen such that several the constants relating to the electron are all equal to one . They are similar to "Schrödinger" units but set the electron mass to unity and allow the gravitational constant to float . The unit of energy in this system is the total energy of the electron in the Bohr atom and called the Hartree energy . The unit of length is the Bohr radius . </Li> <Li> Electronic units are similar to Stoney units but set the electron mass to unity and allow the gravitational constant to float . They are also similar to atomic units but set the speed of light to unity and allow Planck's constant to float . </Li>

What is the name of the standard system of measurement universally used and accepted by scientist