Bonded hard-sphere theory and computer simulations of polyatomic hard-sphere models of alkanes and their derivatives

Autor: Michael D. Amos, Richard P. Sear, George Jackson
Rok vydání: 1993
Předmět:
Zdroj: Molecular Physics. 80:777-788
ISSN: 1362-3028
0026-8976
DOI: 10.1080/00268979300102631
Popis: The equation of state of the first two members of a homologous series of model alkane-like molecules which incorporate the identities of the backbone and substituent atoms as hard-sphere sites is examined. These polyatomic molecules are formed from tangentially bonded hard spheres with diameters σ1 and σ2, where spheres of type 1 make up the backbone of the chain, and spheres of type 2 represent the substituent atoms. The spheres are bonded together in a tetrahedral geometry so that all of the bond angles are ω = 109°; for the second and higher homologues dihedral angles χ about the 1–1 bonds also have to be specified. In order to test the predictions of a recent bonded hard-sphere (BHS) theory, isothermal-isobaric Monte Carlo (MC-NPT) simulations are undertaken for methane- and ethane-like molecules with different diameter ratios σ2/σ1 over a range of densities in the fluid state. In the case of the ethane-like molecules trans (χ = 30°) and freely rotating geometries are examined. The simulation data are...
Databáze: OpenAIRE