A lot of the neo soul chords are regular chords in theory, they are just voiced differently. ex.
Fm9 chord may usually be played
LH RH
F C Eb/ G Ab C Eb
The Neo soul way would be more like
LH RH
G Ab/ Bb Eb G (omitting the F played by the bass player)
or
LH RH
Eb G Ab C/ Eb "F,G" Bb (You can use the F as a grace note going to G for more flava)