Large scale molecular dynamics simulations of a 4-n-pentyl-4′-cyanobiphenyl (5CB) liquid crystalline model in the bulk and as a droplet

• Published in: Computational & theoretical polymer science Vol. 11; no. 5; pp. 375 - 387
• Main Authors: Wang, Zhiqiang, Lupo, James A., Patnaik, Soumya, Pachter, Ruth
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2001
• Subjects: 5CB; CHARMM; Fast multipole method; Large scale molecular dynamics; Liquid crystal droplet; Orientational order; Orientational order; Large scale molecular dynamics; Fast multipole method; Liquid crystal droplet; 5CB; CHARMM
• ISSN: 1089-3156; 1930-8949
• DOI: 10.1016/S1089-3156(01)00017-4

Molecular dynamics simulations for 4-n-pentyl-4′-cyanobiphenyl (5CB) with as many as 944 molecules are reported. The order-N fast multipole method (FMM) is used to treat the long-range interactions. For a droplet of 944 molecules, the simulation shows a correlation between the droplet shape and the nematic order and a strong surface effect; little nematic order is found in a 118 molecule droplet. Simulations of the bulk system result in similar order parameters for both the 118 and 944 molecular ensembles. Although the nematic–isotropic transition was not observed at temperatures as high as 400K using the CHARMM force field, a modification of the force field using ab initio determined partial atomic charges lowers the order parameters.