def NIS(p_nis_c, p_nis_p, n_int_atoms):
    """
    Calculates the predicted binding affinity value
    based on the NIS model.
    """

    return 0.0856851248873*p_nis_p + -0.0685254498746*p_nis_c + 0.0261591389985*n_int_atoms \
        + 3.0124939659498