Metallic high-pressure modifications of main group elements

Abstract

Abstract. The high-pressure structural chemistry of main group elements in the metallic state is reviewed under consideration of more recent determinations of atomic arrangements with to some extend unexpected complexity. Following the concept of the pressure-coordination rule, the number of nearest neighbours is employed as a guiding quantity to reveal systematic trends. Violations of the rule will be mainly discussed in the light of electronic ground state changes upon compression.

High-pressure crystal chemistry of binary intermetallic compounds

“…Pressure-induced changes of the electron configuration and symmetry breaking phase transitions of elemental metals can result in a crystallographic differentation of chemically and physically identical atoms [see, e.g., [38][39][40][41][42][43][44]. In other words, there is only a gradual difference between these high-pressure modifications and binary intermetallic compounds.…”

Pressure-induced normal-incommensurate and incommensurate-commensurate phase transitions in CrOCl

“…The discovery of high-pressure phases of the elements with unexpectedly complex guest-host and incommensurate structures 1 2 3 4 5 put an end to the myth, that atomic arrangements are simplified under high degrees of compression. For complex compounds systematic studies of incommensurate structures are lacking.…”

Electronic structure and bonding in antimony and its high pressure phases

“…The major improvements of the last decade in the high pressure experimental techniques have resulted in many high-pressure crystal structures of elemental solids being successfully solved [1][2][3]. Some more complex atomic patterns have been found, such as arrangements with incommensurate host-guest sublattices, or with unit cells of more than 50 atoms [4][5][6][7].…”