Nuclear mass systematics and nucleon-removal thresholds; application to   17-Na
  A survey of known threshold excitations of mirror systems suggests a means to estimate masses of nuclear systems that are uncertain or not known, as does a trend in the relative energies of isobaric ground states. Using both studies and known mirror-pair energy differences, we estimate the mass of the nucleus 17-Na and its energy relative to the p+16-Ne threshold. This model-free estimate of the latter is larger than that suggested by recent structure models. 
K. Amos, D.van der Knijff, L. Canton, P. R. Fraser, S. Karataglidis,   J. P. Svenne
nucl-th