Journal of Chemical Physics, Vol.101, No.10, 8972-8987, 1994
A Multireference Coupled-Cluster Study of the Ground-State and Lowest Excited-States of Cyclobutadiene
Keywords:BODY PERTURBATION-THEORY;ELECTRONIC-STRUCTURE THEORY;POTENTIAL-ENERGY SURFACES;INCOMPLETE MODEL SPACE;FULL CL TREATMENT;HILBERT-SPACE;VIBRATIONAL-SPECTRA;TRIPLE EXCITATIONS;SINGLE;MOLECULES