A similar ambiguity in the literature surrounds long chain alcohol packing. Following the solved structure for γ-form n-eicosanol , we have constructed a monoclinic γ-form unit cell for C30H61OH (see also Figure ). The unit cell has lattice parameters a = 132.9 Å, b = 4.9 Å, c = 9.0 Å, and β = 93.0° and exhibits staggered chain ends or 'staircase' packing. The C30H61OH SAED pattern can be indexed to the [1 ̅ 0 9] direction in this crystal packing (Figure , S7). However, if the chains were to pack with this staircase symmetry, a crystal sitting flat on a solid support (as used here in TEM and AFM) would not appear in the 'down-chain' orientation as the chains would be tilted relative to a planar support. The experimental observation of such a 'down-chain' orientation suggests the chains pack with more defined lamellar, end-to-end packing, as in the alkane. This arrangement would resemble the known monoclinic β-form (P21/c space group symmetry), such as that reported by Seto for C17H35OH, or an orthorhombic β-form, as suggested by Dorset. Accordingly, we have built C30H61OH β-form unit cells (see also Figure ). The C30H61OH SAED pattern can be indexed to the [001] direction in both of these structures (Figures S5). Inspection of simulated patterns overlaid on top of the experimental SAED patterns from C31H64 crystals, however, reveals marked differences. In the Pbcm pattern, the 01ℓ reflection appears as a single strong peak at ℓ = 32. In the A21am pattern, the 01ℓ reflection splits into two strong peaks at ℓ = 31 and ℓ = 33, in agreement with previous reports by Dorset and colleagues of strong reflections at ℓ = n and ℓ = n + 2 for n carbons in the alkyl chain. Whereas the simulated SAED pattern for the A21am unit cell matches the experimental pattern, the simulated SAED pattern for the Pbcm unit cell shows a spot midway between the two experimental intensity maxima (Figure ). The crystals prepared in the 'chains-flat' orientation are therefore assigned to the A21am space group and the patterns were indexed to the [100]A21am zone axis (Figure ). While we do not exclude the possibility that benzoic acid templating induces a different molecular packing arrangement to the packing arising from solution crystallization, we focus here on the observation of lamellar ordering only visible in the 'chains-flat' orientation, and we draw attention to the changes induced by the incorporation of C30H61OH in like-for-like samples.