Various possible geometric configurations of B4C2, B2C4 clusters were
studied by using quantum-chemical ab initio method, and their vibratio
nal spectra were calculated. The stable configurations of B2C4 are lin
ear or planar; while those of B4C2 are linear, planar or three-dimensi
onal, Therefore, B4C2 is similar to B-6, B2C4 is similar to C-6. It is
an important effect of stability that B4C2 and B2C4 have B-C and C-C
multiple-bond, and a strong conjugated effect.