Some books that are set apart in the Masoretic text are grouped together. For example the Books of Samuel and the Books of Kings are in the LXX one book in four parts called Βασιλειῶν (“Of Reigns”); scholars believe that this is the original arrangement before the book was divided for readability. In LXX, the Books of Chronicles supplement Reigns and it is called Paraleipoménon (Παραλειπομένων—things left out). The Septuagint organizes the minor prophets as twelve parts of one Book of Twelve.[4]
Some scripture of ancient origin are found in the Septuagint but are not present in the Hebrew. These include additions to Daniel and Esther. For more information regarding these books, see the articles Biblical apocrypha, Biblical canon, Books of the Bible, and Deuterocanonical books.
The New Testament makes a number of allusions to and may quote the additional books (as Orthodox Christians aver).
The books are
Tobit,
Judith,
Wisdom of Solomon,
Wisdom of Jesus Seirach,
Baruch,
Epistle of Jeremy (sometimes considered part of Baruch), additions to Daniel (The Prayer of Azarias, the Song of the Three Children, Sosanna and Bel and the Dragon),
additions to Esther,
1 Maccabees,
2 Maccabees,
3 Maccabees,
4 Maccabees,
1 Esdras,
Odes, including the Prayer of Manasses, and
Psalm 151.
The canonical acceptance of these books varies among different Christian traditions, and there are canonical books not derived from the Septuagint; for a discussion see the article on Biblical apocrypha.
en.wikipedia.org/wiki/Septuagint#Books_of_the_Septuagint