Unusual anisotropy of negative Hall states in (TMTSF)(2)PF6

We report an unusual orientation dependence of the negative quantum Hall ef fect (QHE) phases of the organic conductor (TMTSF)(2)PF6. Rotations within the b-c crystallographic plane produce a strong enhancement of the negative QHE states as the sample is tilted away from the normal. For rotations wit hin the Q-c plane, an opposite but somewhat less pronounced effect is obser ved. However, no such orientation dependence is found in the positive QHE s tates. These results establish a fundamental difference between the negativ e and positive QHE states in (TMTSF)(2)PF6. We speculate on the possibility of charge ordering associated with the negative phases.