HT‐NbOsB: Experimental and Theoretical Investigations of a Boride Structure Type Containing Boron Chains and Isolated Boron Atoms.

The new ternary compound Nb1–xOs1+xB (x = 0.17) was synthesized by arc‐melting of the elements in a water‐cooled crucible under an argon atmosphere and was characterized by powder and single‐crystal X‐ray diffraction as well as energy‐dispersive X‐ray spectroscopy (EDX). The compound crystallizes with a new orthorhombic structure type in the space group Pnma (no. 62) with the lattice parameters a = 11.283(2) Å, b = 3.0101(4) Å, and c = 12.883(2) Å. The structure contains isolated boron atoms in osmium trigonal prisms, and boron chains in face‐sharing niobium trigonal prisms. Electronic structure relaxation has confirmed the crystallographic parameters, and crystal orbital Hamilton population (COHP) bonding analysis was used to understand the chemical bonding. It is shown that a local stabilizing effect from replacing Nb with Os is favored despite a global destabilization. [ABSTRACT FROM AUTHOR]