national capital vs capital of Libya

national capital and capital of Libya both are nouns.

Word	Noun	Adjective	Verb	Adverb
national capital	Yes	No	No	No
capital of Libya	Yes	No	No	No

national capital (noun)	capital of Libya (noun)
the capital city of a nation	the capital and chief port and largest city of Libya; in northwestern Libya on the Mediterranean Sea; founded by the Phoenicians in the 7th century BC