dOptimized geometries and C-13 NMR chemical shifts of fullerene C-80 have been calculated by density functional theory using B3LYP/6-31G* for all isolated-pentagon-rule isomers with non-zero HOMO-LOMO gap (isomers 1, 2, 3, 4 and 5). D-2 distorted isomer 7 is predicted as first-order saddle-point by B3LYP/STO-3G The calculated NMR spectrum of isomer 2 agrees well with experiment of Hennrich, confirming the assignment unequivocally. The predicted spectra of other isomers either show unusually. large spectral span or have unusual chemical shifts for some sires, indicating unfavorable electron distribution. Both energetic and NMR properties indicate these isomers are less stable than isomer 2.