C#dim is a diminished, spelled C#, E and G. In Open G tuning (D2 G2 D3 G3 B3 D4) the easiest shape is x65655, which sits at fret 5, needs a barre across 4 strings at fret 5 and mutes 1 string. 12 positions for it are shown below, from the nut up to fret 14.
Notes and intervals
Note
C#
E
G
Interval
1P
3m
5d
12 ways to play it
Ordered by how hard they are to fret, easiest first, one per position on the neck. Fret numbers are relative to the position marked beside each grid.
x65655sits at fret 5, needs a barre across 4 strings at fret 5 and mutes 1 string202022sits at fret 2, needs no stretch at all and lets 2 strings ring open110119xxsits at fret 9, spans 2 frets, lets 1 string ring open and mutes 2 strings1101198xsits at fret 8, spans 3 frets, lets 1 string ring open and mutes 1 string1101401414sits at fret 11, spans 3 frets and lets 2 strings ring open1401401414sits at fret 14, needs no stretch at all and lets 2 strings ring openx014121414sits at fret 12, spans 2 frets, lets 1 string ring open and mutes 1 stringx65055sits at fret 5, spans 1 fret, lets 1 string ring open and mutes 1 stringx02022sits at fret 2, needs no stretch at all, lets 2 strings ring open and mutes 1 string20202xsits at fret 2, needs no stretch at all, lets 2 strings ring open and mutes 1 stringx6505xsits at fret 5, spans 1 fret, lets 1 string ring open and mutes 2 stringsx6565xsits at fret 5, needs a barre across 3 strings at fret 5 and mutes 2 strings
Keys C#dim belongs to
C#dim is diatonic to 8 of the 96 keys this app knows, playing a different role in each.