Structure of liquid linear alcohols

The properties of linear alcohols in the liquid phase are studied by molecular dynamics simulations. We analyze the effects of the use of bond length constraints on the simulation density, self-diffusion constant, and hydrogen-bonding characteristics of the alcohol series. We find that the densities are well-reproduced in each of the cases but that the constraints have clear effects on the value of the diffusion constant and hydrogen-bonding properties, which is probably caused by the use of a gas-phase reference value in the OH bond length constraint. Although finite size effects are found to be present in the hydrogen bond networks, the networks are determined to be composed of chain-type structures that are well-converged. The results indicate that liquid alcohols consist of hydrogen-bonded chains of molecules. This finding can likely be tested experimentally with inelastic X-ray techniques at modern synchrotron radiation sources.