Function psc_model 

fn psc_model(
    t: f64,
    cp: f64,
    cm: f64,
    c0: f64,
    chip: f64,
    _chim: f64,
    r0: f64,
    b0: f64,
) -> (f64, f64)

Paramagnetic-only reconstruction sub-model (pscModel.m).