activation energy vs energy of activation

activation energy and energy of activation both are nouns.

Word	Noun	Adjective	Verb	Adverb
activation energy	Yes	No	No	No
energy of activation	Yes	No	No	No

As nouns, activation energy and energy of activation are synonyms defined as:

activation energy and energy of activation: the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur

activation energy (noun)	energy of activation (noun)
the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur	the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur