national capital vs Austrian capital

national capital and Austrian capital both are nouns.

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

national capital (noun)	Austrian capital (noun)
the capital city of a nation	the capital and largest city of Austria; located on the Danube in northeastern Austria; was the home of Beethoven and Brahms and Haydn and Mozart and Schubert and Strauss