caa a22 4500 465818870 CHVBK 20180323112130.0 cr unu---uuuuu 170327e19900501xx s 000 0 eng 10.1007/BF01112867 doi (NATIONALLICENCE)springer-10.1007/BF01112867 A comparison of variational and non-variational internally contracted multiconfiguration-reference configuration interaction calculations [Elektronische Daten] [Hans-Joachim Werner, Peter Knowles] Summary: The internally contracted multiconfiguration-reference configuration interaction (CMRCI) method and several non-variational variants of this method (averaged coupled pair approximation (ACPF), quasidegenerate variational perturbation theory (QD-VPT), linearized coupled pair many electron theory (LCPMET)) have been employed to compute potential energy functions and other properties for a number of diatomic molecules (F2, O2, N2, CN, CO) using large basis sets and full valence CASSCF reference wavefunctions. In most cases the variational CMRCI wavefunctions yield more accurate spectroscopic constants than any of the employed non-variational methods. Several basis sets are compared for the N2 molecule. It is found that atomic natural orbital (ANO) contractions led to significant errors in the computedr e , ω e , andD e values. Springer-Verlag, 1990 Variational nationallicence Non-variational nationallicence Configuration interaction nationallicence Diatomic molecules nationallicence Werner Hans-Joachim Fakultät für Chemie, Universität Bielefeld, D-4800, Bielefeld, Federal Republic of Germany aut Knowles Peter School of Chemistry and Molecular Sciences, University of Sussex, BN1 9QJ, Falmer, Brighton, UK aut Theoretica chimica acta Springer-Verlag 78/3(1990-05-01), 175-187 0040-5744 78:3<175 1990 78 214 https://doi.org/10.1007/BF01112867 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01112867 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Werner Hans-Joachim Fakultät für Chemie, Universität Bielefeld, D-4800, Bielefeld, Federal Republic of Germany aut NATIONALLICENCE 700 1- Knowles Peter School of Chemistry and Molecular Sciences, University of Sussex, BN1 9QJ, Falmer, Brighton, UK aut NATIONALLICENCE 773 0- Theoretica chimica acta Springer-Verlag 78/3(1990-05-01), 175-187 0040-5744 78:3<175 1990 78 214 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer