%0 Journal Article %1 sheng:164105 %A Sheng, X. W. %A Mentel, Ł. M. %A Gritsenko, O. V. %A Baerends, E. J. %D 2013 %I AIP %J The Journal of Chemical Physics %K chemistry quantum unread %N 16 %P 164105 %R 10.1063/1.4801431 %T A natural orbital analysis of the long range behavior of chemical bonding and van der Waals interaction in singlet Hsub 2: The issue of zero natural orbital occupation numbers %U http://link.aip.org/link/?JCP/138/164105/1 %V 138 %X This paper gives a natural orbital (NO) based analysis of the van der Waals interaction in (singlet) H2 at long distance. The van der Waals interaction, even if not leading to a distinct van der Waals well, affects the shape of the interaction potential in the van der Waals distance range of 5–9 bohrs and can be clearly distinguished from chemical bonding effects. In the NO basis the van der Waals interaction can be quantitatively covered with, apart from the ground state configurations (1σg)2 and (1σu)2, just the 4 configurations (2σg)2 and (2σu)2, and (1πu)2 and (1πg)2. The physics of the dispersion interaction requires and explains the peculiar relatively large positive CI coefficients of the doubly excited electron configurations (2σu)2 and (1πg)2 (the occupancy amplitudes of the 2σu and 1πgx, y NOs) in the distance range 5–9 bohrs, which have been observed before by Cioslowski and Pernal Chem. Phys. Lett. 430, 188 (2006)10.1016/j.cplett.2006.08.111. We show that such positive occupancy amplitudes do not necessarily lead to the existence of zero occupation numbers at some H-H distances.

@article{sheng:164105, abstract = {This paper gives a natural orbital (NO) based analysis of the van der Waals interaction in (singlet) H2 at long distance. The van der Waals interaction, even if not leading to a distinct van der Waals well, affects the shape of the interaction potential in the van der Waals distance range of 5–9 bohrs and can be clearly distinguished from chemical bonding effects. In the NO basis the van der Waals interaction can be quantitatively covered with, apart from the ground state configurations (1σg)2 and (1σu)2, just the 4 configurations (2σg)2 and (2σu)2, and (1πu)2 and (1πg)2. The physics of the dispersion interaction requires and explains the peculiar relatively large positive CI coefficients of the doubly excited electron configurations (2σu)2 and (1πg)2 (the occupancy amplitudes of the 2σu and 1πgx, y NOs) in the distance range 5–9 bohrs, which have been observed before by Cioslowski and Pernal [Chem. Phys. Lett. 430, 188 (2006)]10.1016/j.cplett.2006.08.111. We show that such positive occupancy amplitudes do not necessarily lead to the existence of zero occupation numbers at some H-H distances.}, added-at = {2013-05-01T13:15:22.000+0200}, author = {Sheng, X. W. and Mentel, {\L}. M. and Gritsenko, O. V. and Baerends, E. J.}, biburl = {https://www.bibsonomy.org/bibtex/228e1bf6a1c4708e4536fb76317915696/drmatusek}, doi = {10.1063/1.4801431}, eid = {164105}, interhash = {8f1dd81a131eb234438293cee93267cb}, intrahash = {28e1bf6a1c4708e4536fb76317915696}, journal = {The Journal of Chemical Physics}, keywords = {chemistry quantum unread}, month = apr, number = 16, numpages = {11}, pages = 164105, publisher = {AIP}, timestamp = {2013-05-01T13:15:22.000+0200}, title = {A natural orbital analysis of the long range behavior of chemical bonding and van der Waals interaction in singlet H[sub 2]: The issue of zero natural orbital occupation numbers}, url = {http://link.aip.org/link/?JCP/138/164105/1}, volume = 138, year = 2013 }