harmonious vs harmony

harmonious is not a noun while harmony is a noun.

Word	Noun	Adjective	Verb	Adverb
harmonious	No	Yes	No	No
harmony	Yes	No	No	No

harmonious (noun)	harmony (noun)
	an agreeable sound property
	compatibility in opinion and action
	agreement of opinions
	the structure of music with respect to the composition and progression of chords
	a harmonious state of things in general and of their properties (as of colors and sounds); congruity of parts with one another and with the whole

harmonious (adjective)	harmony (adjective)
musically pleasing
exhibiting equivalence or correspondence among constituents of an entity or between different entities
existing together in harmony
suitable and fitting