national capital vs Mexican capital

national capital and Mexican capital both are nouns.

Word	Noun	Adjective	Verb	Adverb
national capital	Yes	No	No	No
Mexican capital	Yes	No	No	No

national capital (noun)	Mexican capital (noun)
the capital city of a nation	the capital and largest city of Mexico is a political and cultural and commercial and industrial center; one of the world's largest cities