All‐electron relativistic computations on the low‐lying electronic states, bond length, and vibrational frequency of CeF diatomic molecule with spin–orbit coupling effects. Issue 16 (30th January 2018) - Kondo, Yusuke
Abstract : Ab initio all‐electron computations have been carried out for Ce + and CeF, including the electron correlation, scalar relativistic, and spin–orbit coupling effects in a quantitative manner. First, the n ‐electron valence state second‐order multireference perturbation theory (NEVPT2) and spin–orbit configuration interaction (SOCI) based on the state‐averaged restricted active space multiconfigurational self‐consistent field (SA‐RASSCF) and state‐averaged complete active space multiconfigurational self‐consistent field (SA‐CASSCF) wavefunctions have been applied to evaluations of the low‐lying energy levels of Ce + with [Xe]4f 1 5d 1 6s 1 and [Xe]4f 1 5d 2 configurations, to test the accuracy of several all‐electron relativistic basis sets. It is shown that the mixing of quartet and doublet states is essential to reproduce the excitation energies. Then, SA‐RASSCF(CASSCF)/NEVPT2 + SOCI computations with the Sapporo(‐DKH3)‐2012‐QZP basis set were carried out to determine the energy levels of the low‐lying electronic states of CeF. The calculated excitation energies, bond length, and vibrational frequency are shown to be in good agreement with the available experimental data. © 2018 Wiley Periodicals, Inc. Abstract : Ab initio all‐electron multiconfigurational computations have been carried out for the energy levels of the low‐lying near‐degenerate electronic states of Ce + and CeF with the Sapporo‐QZP basis set, including the electron correlation, scalar relativistic, and spin–orbit coupling effects in a quantitative manner. The calculated excitation energies, bond length, and vibrational frequency are shown to be in good agreement with the available experimental data.