title: Possible superhardness of CrB4.
abstract: Chromium tetraboride [orthorhombic, space group Pnnm (No. 58), a = 474.65(9) pm, b = 548.0(1) pm, c = 286.81(5) pm, and R value (all data) = 0.041], formerly described in space group Immm, was found not to be superhard, despite several theory-based prognoses. CrB(4) shows an almost temperature-independent paramagnetism, consistent with low-spin Cr(I) in a metallic compound. Conductivity measurements confirm the metallic character.
authors.affiliation: Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Technische Universität Darmstadt, Petersenstrasse 18/32, 64287 Darmstadt, Germany.
authors.forename: Arno
authors.initials: A
authors.lastname: Knappschneider
authors.forename: Christian
authors.initials: C
authors.lastname: Litterscheid
authors.forename: Dmytro
authors.initials: D
authors.lastname: Dzivenko
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Kurzman
authors.forename: Ram
authors.initials: R
authors.lastname: Seshadri
authors.forename: Norbert
authors.initials: N
authors.lastname: Wagner
authors.forename: Johannes
authors.initials: J
authors.lastname: Beck
authors.forename: Ralf
authors.initials: R
authors.lastname: Riedel
authors.forename: Barbara
authors.initials: B
authors.lastname: Albert