Origen's (186-254) colossal critical edition of the Old Testament in Hebrew and Greek.
This "six-fold" Bible, comprising about 50 large volumes, is arranged in six parallel columns which contain the Hebrew text in Hebrew (square) and Greek characters, the Septuagint, and three other Greek versions.
Origen's purpose, as regards the Septuagint, was to show its relation to the Hebrew text and the other Greek versions.
Only one of the columns has survived, which is that exhibiting the text of the Septuagint.
New Catholic Dictionary