Molecular dynamics simulation of liquid carbon disulphide with a harmonic intramolecular potential

Structure and dynamics of liquid CS2: Going from ambient to elevated pressure conditions

Molecular dynamics simulation studies were performed to investigate the structural and dynamic properties of liquid carbon disulfide (CS₂) from ambient to elevated pressure conditions. The results obtained have revealed structural changes at high pressures, which are related to the more dense packing of the molecules inside the first solvation shell. The calculated neutron and X-ray structure factors have been compared with available experimental diffraction data, also revealing the pressure effects on the short-range structure of the liquid. The pressure effects on the translational, reorientational, and residence dynamics are very strong, revealing a significant slowing down when going from ambient pressure to 1.2 GPa. The translational dynamics of the linear CS₂ molecules have been found to be more anisotropic at elevated pressures, where cage effects and librational motions are reflected on the shape of the calculated time correlation functions and their corresponding spectral densities.

Pressure dependence of local structure in liquid carbon disulfide

High pressure x-ray diffraction measurements on liquid carbon disulfide up to 1.2 GPa are performed by using an energy dispersion method. The results are compared with a molecular dynamics calculation with usual Lennard-Jones potential. They give very good agreement for all pressures measured. It becomes clear that the liquid structure changes like hard core liquid up to the pressure just below crystallizing point. The relation between structural change and optical response at high pressure is discussed.

Calculation of crystal and molecular structures of carbon disulfide CS2

Crystal and molecular structures of carbon disulfide CS(2) were investigated by molecular packing analysis with a computed dynamical model. This model includes thermal motions, molecular deformations, and anisotropic atomic repulsive interactions. Several crystalline structures with orthorhombic symmetry Cmca have been found by the calculation. The lowest energy structure agrees with the experimental one. The temperature dependence of the crystal structure parameters reproduces the general features and the particular increase with decreasing temperature of the lattice parameter c (and orientational angle psi) as determined by x-ray diffraction or neutron scattering experiments. The pressure behavior of the crystal structure parameters up to 12 GPa at room temperature is also correctly reproduced.