KT (energy)

kT is the product of the Boltzmann constant, k, and the temperature, T. This product is used in physics as a scale factor for energy values in molecular-scale systems, as the rates and frequencies of many processes and phenomena depend not on their energy alone, but on the ratio of that energy and kT, that is, on . For a system in equilibrium in canonical ensemble, the probability of the system being in state with energy E is proportional to
More fundamentally, kT is the amount of heat required to increase the thermodynamic entropy of a system by k.
In physical chemistry, as kT often appears in the denominator of fractions, sometimes β = is used instead of kT, turning into.

''RT''

RT is the product of the molar gas constant, R, and the temperature, T. This product is used in physics and chemistry as a scaling factor for energy values in macroscopic scale, as many processes and phenomena depend not on the energy alone, but on the ratio of energy and RT, i.e.. The SI units for RT are joules per mole.
It differs from kT only by a factor of the Avogadro constant, N_A. It is of dimension ML²T⁻², expressed in SI units as joules :