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Force‐field modeling through quantum mechanical calculations: Molecular dynamics simulations of a nematogenic molecule in its condensed phases
Author(s) -
Cacelli Ivo,
Lami Carlo Federico,
Prampolini Giacomo
Publication year - 2009
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.21062
Subject(s) - molecular dynamics , isotropy , force field (fiction) , quantum , dimer , potential energy , statistical physics , molecule , materials science , field (mathematics) , physics , computational chemistry , classical mechanics , chemistry , quantum mechanics , mathematics , nuclear magnetic resonance , pure mathematics
Interaction energy of the 4‐ n ‐pentyloxy‐4′‐cyanobiphenyl (5OCB) dimer is computed at MP2 level, for many geometrical arrangements using the Fragmentation Reconstruction Method (FRM). DFT calculations are performed for a number of geometries of the monomer. The resulting database is used to parameterize an atomistic intra‐ and inter‐molecular force‐field suitable for classical bulk simulations. Several structural and dynamical properties in 5OCB isotropic and liquid crystalline phases are computed from molecular dynamics simulation mainly in the NPT ensemble. Lengthy runs (more than 70 ns) and large sample sizes (up to 806 molecules) were used to determine the nematic to isotropic transition temperature up to a precision of few K. Good agreement was found in most of the investigated properties, thus validating the accuracy of the proposed model potential, only derived by quantum mechanical calculations. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009