New force-field for organosilicon molecules in the liquid phase

Miguel Jorge, Andrew W. Milne, Maria Cecilia Barrera, José R. B. Gomes

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)
29 Downloads (Pure)


In this paper, we present a new molecular model that can accurately predict thermodynamic liquid state and phase-change properties for organosilicon molecules including several functional groups (alkylsilane, alkoxysilane, siloxane and silanol). These molecules are of great importance in geological processes, biological systems and material science, yet no force field currently exists that is widely applicable to organosilicates. The model is parameterized according to the recent Polarization-Consistent Approach (PolCA), which allows for polarization effects to be incorporated into a non-polarizable model through post facto correction terms, and is therefore consistent with previous parameterizations of the PolCA force field. Alkyl groups are described by the United-Atom approach, bond and angle parameters were taken from previous literature studies, dihedral parameters were fitted to new quantum chemical energy profiles, point charges were calculated from quantum chemical optimizations in a continuum solvent, and Lennard-Jones dispersion/repulsion parameters were fitted to match the density and enthalpy of vaporization of a small number of selected compounds. Extensive validation efforts were carried out, after careful collection and curation of experimental data for organosilicates. Overall, the model performed quite well for the density, enthalpy of vaporization, dielectric constant and self-diffusion coefficient, but slightly overestimated the magnitude of self-solvation free energies. The modular and transferable nature of the PolCA force field allows for further extensions to other types of silicon-containing compounds.
Original languageEnglish
Pages (from-to)54-69
Number of pages16
JournalACS Physical Chemistry Au
Issue number1
Early online date27 Aug 2021
Publication statusPublished - 24 Nov 2021


  • organosilicates
  • silica
  • molecular model
  • molecular dynamics
  • polarization


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