Similar to Wallace and Sansom, Hilder et al28 used steered molecular dynamics, this time using an all-atom force field. They investigated the stability of a CNT 0.9 nm in diameter and with a length of 3.4 nm in a lipid bilayer. Because all atoms were explicitly represented, rather than a generic hydrophilic terminus, their NTs were terminated with carbonyl groups (C = O). In agreement with Lopez et al, they determined a deep energy well of 250–300 kcal mol−1, suggesting that the NT is likely to be confined to the center of the lipid bilayer.