The FeO+cation has been examined by using the following ab initio methods: (i) the single determinant oriented quadratic configuration interaction (QCISD(T)) and coupled-cluster CCSD(T) approaches, (ii) the multiconfiguration wavefunction-based complete active space SCF/multireference CI (CAS-MRCI) method and complete active space/perturbation theory (CASPT2). The effects of different basis sets and the inclusion of core electrons in the correlation treatment have been evaluated. The experimental bond energy is well reproduced by the CASPT2 calculations employing a large basis set. The Devalues calculated by the QCISD(T) method are almost identical to the CAS-MRCISD values, which in turn are slightly lower than those obtained with CASPT2. The computer-time requirements for the different methods are compared. © 1993.
Fiedler, A., Hrušák, J., Koch, W., & Schwarz, H. (1993). The energetical and structural properties of FeO+. An application of multireference perturbation theory. Chemical Physics Letters, 211(2–3), 242–248. https://doi.org/10.1016/0009-2614(93)85192-Q