Helium chemistry is notoriously very impervious. It is therefore certainly no surprise that, for example, beryllium and helium atoms, in their ground state, do not bind. Full configuration-interaction calculations show that the same turns out to be true, save for a long-range shallow attraction, for the Be+ + He system. However, quite astonishingly, when one electron is re-added to Be+ in an excited 2p(pi) or 3s orbital (Be P-1 or S-1), a bound adduct with He is formed, at an interatomic separation as short as 1.5 angstrom. Understanding why this happens reveals an unsuspected chemical mechanism that stabilizes helium compounds at the molecular level.
Chemical Bond Mechanism for Helium Revealed by Electronic Excitation
Belpassi Leonardo;Pirani Fernando;
2019
Abstract
Helium chemistry is notoriously very impervious. It is therefore certainly no surprise that, for example, beryllium and helium atoms, in their ground state, do not bind. Full configuration-interaction calculations show that the same turns out to be true, save for a long-range shallow attraction, for the Be+ + He system. However, quite astonishingly, when one electron is re-added to Be+ in an excited 2p(pi) or 3s orbital (Be P-1 or S-1), a bound adduct with He is formed, at an interatomic separation as short as 1.5 angstrom. Understanding why this happens reveals an unsuspected chemical mechanism that stabilizes helium compounds at the molecular level.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
