Solid Phases of Cyclopentane: Combined Experimental and Simulation Study

The phase diagram of cyclopentane has been studied by powder neutron diffraction, providing diffraction
patterns for phases I, II, and III, over a range of temperatures and pressures. The putative phase IV was not
observed. The structure of the ordered phase III has been solved by single-crystal diffraction. Computational
modeling reveals that there are many equienergetic ordered structures for cyclopentane within a small energy
range. Molecular dynamics simulations reproduce the structures and diffraction patterns for phases I and III
and also show an intermediate disordered phase, which is used to interpret phase II.