capital of Antigua and Barbuda vs national capital

capital of Antigua and Barbuda and national capital both are nouns.

Word	Noun	Adjective	Verb	Adverb
capital of Antigua and Barbuda	Yes	No	No	No
national capital	Yes	No	No	No

capital of Antigua and Barbuda (noun)	national capital (noun)
the capital and largest city of Antigua and Barbuda; located on the island of Antigua	the capital city of a nation