what is the rhyme scheme of the poem the the rime of the ancient mariner?

"The Rime of the Ancient Mariner" is written in the form of a ballad. The primary rhyme scheme is ABAB or ABABAB. However, some other rhyme schemes can also be found like, AABCCBDDB, ABCCB and ABAAB. The poem is written in the form of a quatrain with four lines in each stanza.