C# Minor 9b5, 3rd inversion (B in the bass)
Also written as C#m9b5/B.
Notes, from the bass up
B (bass)D#C#EG
The same notes as C# Minor 9b5 (B, D#, C#, E and G), rearranged so B is the lowest note. Use it to move between chords with smaller jumps across the keyboard.