Function polymers::physics::single_chain::swfjc::thermodynamics::isotensional::legendre::helmholtz_free_energy_per_link

pub fn helmholtz_free_energy_per_link(
    link_length: &f64,
    hinge_mass: &f64,
    well_width: &f64,
    force: &f64,
    temperature: &f64
) -> f64

The Helmholtz free energy per link as a function of the applied force and temperature, parameterized by the link length, hinge mass, and well width.