# Load the COSMO species
database = CosmoRSSpeciesDatabase()
water = database.exportSpecies('water')
acetonitrile = database.exportSpecies('acetonitrile')
acetonitrile.setAntoineA(5.93296 * bar)
acetonitrile.setAntoineB(2345.829 * Kelvin)
acetonitrile.setAntoineC(43.815 * Kelvin)

# Create a mixture
mixture = CosmoRSMixture([(water, 0.5), (acetonitrile, 0.5)])

# Determine the vapor pressure.
vapor_pressure = VaporPressure(
    mixture,
    298*Kelvin,
    parameters=CosmoRSParameters(),
)

# Retrieve the vapor pressure of acetonitrile.
p_vap = vapor_pressure.vaporPressure()[1].convertTo(bar)
nlprint(f'The vapor pressure of acetonitrile is {p_vap}')