capital of Greece vs Greek capital

capital of Greece and Greek capital both are nouns.

Word	Noun	Adjective	Verb	Adverb
capital of Greece	Yes	No	No	No
Greek capital	Yes	No	No	No

As nouns, capital of Greece and Greek capital are synonyms defined as:

capital of Greece and Greek capital: the capital and largest city of Greece; named after Athena (its patron goddess)

Other synonyms of capital of Greece include Athens, Athinai.

capital of Greece (noun)	Greek capital (noun)
the capital and largest city of Greece; named after Athena (its patron goddess)	the capital and largest city of Greece; named after Athena (its patron goddess)