/usr/share/columbus1/greekAccentedLetterGroups.txt is in libcolumbus1-common 1.1.0+15.10.20150806-0ubuntu12.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | αά
εέ
ηή
ιίϊΐ
οό
υύϋΰ
ωώ
|