Information on mass chains and nuclides available on this website:

WWW TUNL

¹³Li has not been observed. The calculated value of its mass excess is 60.34 MeV [see (81AJ01)]: ¹³Li would then be unstable with respect to ¹¹Li + 2n by 3.26 MeV. (BO80T) have not observed ¹³Li in the bombardment of ¹²⁴Sn by 6.7 GeV protons but state that the statistics were poor in the region of interest and that it is not excluded that ¹³Li may be stable. See also (AN83D; theor.).