<br/>Electrides, in which electrons occupy interstitial regions in the crystal and behave as anions, have been known for some time, in liquid and solid phases. They also appear as new phases for many elements (and compounds) under high pressure. In work with Mao-Sheng Miao we describe high pressure electrides (HPEs) by treating electrons in the interstitial sites as filling the quantized orbitals of the space enclosed by the surrounding atom cores, generating what we call an interstitial quasi-atom, ISQ. With increasing pressure, the energies of the valence orbitals of atoms increase more significantly than the ISQ levels, orthogonality to the atom cores effectively being responsible.  At a high enough pressure, which depends on the element and its orbitals, electron transfer to the interstitial space and the formation of an HPE may ensue. By using a He lattice model to compress atoms and an interstitial space, we are able to semi-quantitatively explain and predict the propensity of various elements to form HPEs. The slopes in energy of various orbitals with pressure (s&gt;p&gt;d for a given principal quantum number) are essential for identifying trends across the entire periodic table.<br/>          ISQs  can behave as radicals or anions, and in certain circumstances can form quasimolecules. We indicate evidence for such a system in Li under pressure.<br/>

High pressure electrides: A chemical and physical theory

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.