Structure, effective pair potential and properties of halothane

Halothane, 2-bromo-2-chloro-1,1,1-trifluoroethane, is an important inhalation general anesthetic. We performed energy minimization within the Car-Parrinello scheme of density functional theory to obtain the detailed structure of a halothane molecule, in the gas phase. Then, effective model pair potentials for a flexible halothane molecule have been developed that describe halothane in solution around room temperature. The potential parameters were fitted to reproduce the known density at 298 K. Constant pressure and temperature molecular dynamics simulations were carried out at room temperature as well as at 310 K. The results are in excellent agreement with the available experimental data.