Figure 2
Ab initio potential energy surface scans of (a) θ1 and (b) θ2 for piracetam. The scans were carried out in both directions. The discrepancy between the original scans (triangles) and reverse scans (squares) results from the dependence of the final conformer on the starting conformer in multiple-minima regions during the local partial optimization at each point and typically indicates a difference in (a) θ2 and (b) θ1. |