Potential energy curves, transition dipole moments, and radiative lifetimes of KBe molecule

An ab initio calculations on the ground and low-lying excited states (X²Σ⁺, 2²Σ⁺, 3²Σ⁺, 1⁴Π, 2⁴Π, 1⁴Σ⁺, 2⁴Σ⁺, and 3⁴Σ⁺) of KBe molecule have been performed using multireference configuration interaction (MRCI) plus Davidson corrections (MRCI+Q) approach with all electron basis set aug-cc-pCV5Z-DK for Be and def2-AQZVPP-JKFI for K. The 3²Σ⁺, 1⁴Π, 2⁴Π, 1⁴Σ⁺, 2⁴Σ⁺, and 3⁴Σ⁺ states are investigated for the first time. Inner shell electron correlations are computed on the potential energy curves (PECs) calculations. The spectroscopic and molecular parameters are also predicted. In addition, The transition properties including transition dipole moment, Franck-Condon factors q_v'v'', Einstein coefficients A_v'v'', and the radiative lifetimes τ_v' for the 2²Σ⁺-X²Σ⁺, 3²Σ⁺-X²Σ⁺, and 2⁴Π-1⁴Π transitions are predicted at the same time.