“…In this work, we have carried out the multi-reference configuration interaction (MRCI) [26,27] computations on three 2 Σ + , two 4 Π, and three 4 Σ + states of KBe molecule based on inner shell electron correlations. At the present time, Li, [28] Zhu, [29] Wang, [30] Liu, [31] and Xing [32] have adopted the MRCI method to calculate the ground and low-lying states of CS + , AsO + , P 2 , GeO, and CF + , and the obtained results conform to the experimental values. No experimental data have yet been found in the literature for these states, and our main goal is to provide accurate spectroscopic parameters for these states.…”