TY - JOUR
T1 - CO2+
T2 - A difficult molecule for electron correlation
AU - Gellene, Gregory I.
N1 - Funding Information:
This material is based in part on work supported by the Texas Advanced Research Program under Grant 003644-071. The research was also supported by the Robert A. Welch Foundation and the National Science Foundation (CHE95-51008).
PY - 1998/5/1
Y1 - 1998/5/1
N2 - Although unrestricted, Hartree-Fock calculations correctly predict a D∞h equilibrium geometry for CO2+, inclusion of electron correlation by methods limited to double substitutions result in the incorrect prediction of a C∞v equilibrium geometry. Additional electron correlation recovers the correct equilibrium geometry. This unusual pattern of first having, and then losing, and then regaining symmetry with increasing electron correlation is rationalized in terms balancing the contribution of a valence bond configuration having two C-O double bonds which favors a D∞h structure and one having a single and a triple C-O bond which favors a C∞v structure.
AB - Although unrestricted, Hartree-Fock calculations correctly predict a D∞h equilibrium geometry for CO2+, inclusion of electron correlation by methods limited to double substitutions result in the incorrect prediction of a C∞v equilibrium geometry. Additional electron correlation recovers the correct equilibrium geometry. This unusual pattern of first having, and then losing, and then regaining symmetry with increasing electron correlation is rationalized in terms balancing the contribution of a valence bond configuration having two C-O double bonds which favors a D∞h structure and one having a single and a triple C-O bond which favors a C∞v structure.
UR - http://www.scopus.com/inward/record.url?scp=0032065177&partnerID=8YFLogxK
U2 - 10.1016/S0009-2614(98)00188-2
DO - 10.1016/S0009-2614(98)00188-2
M3 - Article
AN - SCOPUS:0032065177
SN - 0009-2614
VL - 287
SP - 315
EP - 319
JO - Chemical Physics Letters
JF - Chemical Physics Letters
IS - 3-4
ER -