Dilithium, Li2, is a strongly electrophilic, diatomic molecule comprising two lithium atoms covalently bonded together. Li2 is known in the gas phase. It has a bond order of 1, an internuclear separation of 267.3 pm and a bond energy of 101 kJ mol−1.[1]The electron configuration of Li2 may be written as σ2. References [1] Chemical Bonding, Mark J. Winter, Oxford University Press, 1994, ISBN 0-19-855694-2 摘自维基