F Minor 9b5, 1st inversion (Ab in the bass)
Also written as Fm9b5/Ab.
Notes, from the bass up
Ab (bass)CbEbGF
The same notes as F Minor 9b5 (Ab, Cb, Eb, G and F), rearranged so Ab is the lowest note. Use it to move between chords with smaller jumps across the keyboard.