Looking for the stable isomers of [N,C,C,O]+ system

A detailed singlet potential energy surface of the [N,C,C,O]+ system is investigated by means of MP2 and QCISD(T) (single-point) methods. Four linear isomers of [N,C,C,O]+ system, NCCO+, CNCO+, COCN+ and CCNO+, are found to be kinetically stable and should be experimentally observable at extra low temperatures and pressures. The linear isomer NCCO+ is thermodynamically the most stable species followed by CNCO+, COCN+ and CCNO+. No kinetically stable cyclic isomers are found. Furthermore, the structural nature of stable isomers is discussed based on computed bond lengths, bonding characteristics, and positive charge distribution.