Structure of liquids composed of shifted dipole linear molecules

Lago, S.; López-Vidal, Silvia; Garzón, B.; Mejías, José A.; Anta, Juan A.; Calero, Sofı́a

doi:10.1103/physreve.68.021201

Cited by 12 publications

(17 citation statements)

References 22 publications

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“…26 The main advantage of the GB-K potential is that it combines, within the intrinsic limitations of the rigid models, a qualitatively more adequate description of both, the pair interactions and the molecular shape of the typical mesogens, in comparison to previous models, whereas it keeps a comparable compactness and numerical efficiency in its formulation. This property can be interpreted as being a direct consequence of the greater dispersive interactions assigned in the GB-K fluid to specific pair orientations, such as the parallel side-to-side configuration.…”

Section: Discussionmentioning

confidence: 99%

A novel orientation-dependent potential model for prolate mesogens

Martínez–Haya

Cuetos

Lago

et al. 2004

The Journal of Chemical Physics

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An intermolecular potential is introduced for the study of molecular mesogenic fluids. The model combines distinct features of the well-known Gay-Berne and Kihara potentials by incorporating dispersive interactions dependent on the relative pair orientation to a spherocylinder molecular core. Results of a Monte Carlo simulation study focused on the liquid crystal phases exhibited by the model fluid are presented. For the chosen potential parameters, molecular aspect ratio L*=5 and temperatures T*=2, 3, and 5, isotropic, nematic, smectic-A, and hexatic phases are found. The location of the phase boundaries as well as the equation of state of the fluid and further thermodynamical and structural parameters are discussed and contrasted to the Kihara fluid. In comparison to this latter fluid, the model induces the formation of ordered liquid crystalline phases at lower packing fractions and it favors, in particular, the appearance of layered hexatic ordering as a consequence of the greater attractive interaction assigned to the parallel side-to-side molecular pair configurations. The results contribute to the evaluation of the role of specific interaction energies in the mesogenic behavior of prolate molecular liquids in dense environments.

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Section: Discussionmentioning

confidence: 99%

A novel orientation-dependent potential model for prolate mesogens

Martínez–Haya

Cuetos

Lago

et al. 2004

The Journal of Chemical Physics

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“…More realistic models to represent the molecule's charge distribution have been considered in several studies [21][22][23][24][25][26]. The polarizability of the molecules was considered by several authors [27][28][29].…”

Section: Introductionmentioning

confidence: 99%

The structure of strongly dipolar hard sphere fluids with extended dipoles by Monte Carlo simulations

et al. 2010

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We have investigated the structural change of dipolar hard sphere fluid while we change the dipole from an idealized point dipole (pDHS fluid) to a physically more realistic extended dipole (eDHS fluid) by increasing the distance d of the two point charges ±q while keeping the dipole moment µ = qd fixed. We discuss our results on the basis of the first-and second-rank orientational order parameters, angular distribution functions, chain-length distributions, and snapshots. At a low density, we have found chain formation with longer chains as the distance d is increased. At a high density, we have found phase transition from an orientationally ordered ferroelectric nematic phase (at low d) into an isotropic liquid containing chains (at large d).

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“…To make clear the pair structure, Table IV shows the main geometrical values corresponding to the configurations that a pair of molecules can adopt ͑see Appen-dix͒. 19 All these geometrical details are shown in Table IV and can be compared with the simulation results in Tables II and III. 2͑a͔͒ corresponds to a null quadrupole where molecules are parallel and each atom is confronted to the corresponding atom of a different molecule and sensibly at the same distance than the molecular centers.…”

Section: Discussionmentioning

confidence: 99%

“…123, 184502 ͑2005͒ above may give further explanation. On the other hand, one can wonder why liquid of acetylene is more poorly described by a nonpolar reference system than chlorine ͑L * = 0.5͒ 18 or even 2-butyne ͑L * = 1.1͒, 19 both of them are more quadrupolar than nitrogen and longer than acetylene. Indeed, the symmetry of a pair of molecules changes from a symmetry point group D 2h ͓Fig.…”

Section: -7mentioning

confidence: 99%

A new insight on the structural changes of linear quadrupole liquids

Cortada

Calero

Lago

2005

The Journal of Chemical Physics

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Molecular-dynamics simulations for linear quadrupole liquids are presented. The study is carried out for two different molecular lengths at constant density and a number of temperatures and quadrupole moments. All the simulated thermodynamic states correspond to the condensed phases and some of them show typical features of a solid structure. Furthermore, a change on the preferred intermolecular orientation in the liquid phase is observed from a shifted parallel molecular arrangement to a perpendicular orientation as the quadrupole raises. This change depends on the quadrupole moment as well as on the molecular length and is put in relation with the solid structure of different "diatomic" molecules such as nitrogen, ethane, and acetylene. The appearance of a plastic solid phase at low quadrupole moment and density is also justified. A thoroughly discussion about the availability of classical perturbation theories for this kind of systems is presented.

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Structure of liquids composed of shifted dipole linear molecules

Cited by 12 publications

References 22 publications

A novel orientation-dependent potential model for prolate mesogens

A novel orientation-dependent potential model for prolate mesogens

The structure of strongly dipolar hard sphere fluids with extended dipoles by Monte Carlo simulations

A new insight on the structural changes of linear quadrupole liquids

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