31 KB433 KB28 KB199820252006Jamnik, AndrejZhou, Shiqištevilka:3letnik:537 stranistr. 350-356ISSN:1318-0207COBISSID:27970053URN:URN:NBN:SI:doc-EQ2UOU95enSlovensko kemijsko društvoActa chimica slovenicafizikalna kemijafluidimetoda Monte CarlomodeliMonte Carlo methodnehomogeni sistemiračunalniška simulacijastrukturateorija gostotnega funkcionalaPerturbation density functional theory for inhomogeneous fluids|A recently developed third order+second order perturbation density functional approximation (DFA) is briefly described. The applicability of this theory is demonstrated in the study of the density profiles of Lennard-Jones (LJ) fluid next to a large hard sphere (mimicking a colloidal particle) of various sizes.The accuracy of DFA predictions is tested against the results of a grand canonical ensemble Monte Carlo simulation. The chosen density and potential parameters for the equilibrium bulk LJ fluid correspond to the conditions situated at "dangerous" regions of the phase diagram, i.e. near thecritical temperature or close to the gas-liquid coexistence curve. It is found that the DFA theory performs successfully for both supercritical and subcritical temperatures. It is also shown that the ćuniversalityć of the adjustable parameter associated with this theory holds also in the present case of a large spherical particle as a source of external potential. Here the term universality means independence of this parameter on the particular external field responsible for the generation of a non-uniform density profile of the fluid. This DFA results can be used as a useful starting point for further investigation of solvent-induced excess potential of mean force in the similar systemsOpisane so osnovne značilnosti ene inačic teorije gostotnega funkcionala, to je perturbacijske teorije drugega in tretjega reda. Uporabnost te teorije smo preizkusili pri obravnavi strukture Lennard-Jones-ove (LJ) enostavne tekočine okoli velikih togih kroglic, ki ponazarjajo koloidne delce v disperziji. Zanesljivost teorijskih rezultatov smo preverili z računalniško simulacijo Monte Carlo odprtega sistema, ki omogoča obravnavo ravnotežja med nehomogenim in homogenim sistemom. Račune smo izvedli pri dveh temperaturah, ki sta bili le malo pod oz. nad kritično vrednostjo. Dobro ujemanje rezultatov obeh metod dokazuje, da je predlagana teorija zelo primerna za obravnavo strukturnih značilnosti nehomogenih sistemov. Rezultate bomo uporabili kot izhodišče za nadaljno obravnavo potenciala srednje sile med koloidnimi delci v sorodnih sistemihTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaSlovensko kemijsko društvo