The geometry of N@C-60 was optimized by using ab initio Unrestricted Hartre
e-Fock method. The results show that nitrogen is in the center of the cage
in the form of atom basically, but there are some interactions between nitr
ogen atom and carbon cage. That is in agreement with the experimental resul
ts. We further calculated the vibrational spectrum of N@C-60 and compared i
t with C-60.