  Proton threshold states in 23Mg are important for the astrophysically
relevant proton capture reaction 22Na(p,gamma)23Mg. In the indirect
determination of the resonance strength of the lowest states, which were not
accessible by direct methods, some of the spin-parity assignments remained
experimentally uncertain. We have investigated these states with Shell Model,
Coulomb displacement, and Thomas-Ehrman shift calculations. From the comparison
of calculated and observed properties we relate the lowest relevant resonance
state at E=7643 keV to an excited 3/2+ state in accordance with a recent
experimental determination by Jenkins et al.. From this we deduce significantly
improved values for the 22Na(p,gamma)23Mg reaction rate at stellar temperatures
below T_9=0.1K.
