Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com
Dr. Eloy Ramos‐Cordoba
Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com
Prof. Xabier Lopez
Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com
Prof. Miquel Solà
Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química University of Girona C/ Maria Aurèlia Capmany, 69 17003 Girona Catalonia Spain
Prof. Jesus M. Ugalde
Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com
Dr. Eduard Matito
Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC) P.K. 1072 20080 Donostia, Euskadi Spain E-mail: eloy.raco_at_gmail.com
Abstract We analyze the Coulomb hole of Ne from highly‐accurate CISD wave functions obtained from optimized even‐tempered basis sets. Using a two‐fold extrapolation procedure we obtain highly accurate results that recover 97 % of the correlation energy. We confirm the existence of a shoulder in the short‐range region of the Coulomb hole of the Ne atom, which is due to an internal reorganization of the K‐shell caused by electron correlation of the core electrons. The feature is very sensitive to the quality of the basis set in the core region and it is not exclusive to Ne, being also present in most of second‐row atoms, thus confirming that it is due to K‐shell correlation effects.