The results of the theoretical study on PuX2+ (X = O, H, N, C) using densit
y functional method (B3LYP) show that PuO2+ PuH2+, PuN2+ and PuC2+ can be s
table. Ground electronic states are X(5)Sigma (-)(PuO2+), X(8)Sigma (-) (Pu
H2+) X(4)Sigma (+) (PuN2+) and X(9)Sigma (-) (PuC2+), and their potential e
nergy functions are in good agreement with the Murrell - Sorbie function, a
nd their force constants and spectroscopic data have been worked out.