Chemical binding and energy band structure of vanadium monocarbide

Abstract

The band structure of vanadium monocarbide is calculated by the tight-binding method. A set of ten Bloch sums of the 3d, 4s and 2s, 2p states of the free V and C atoms is used as the basis functions. The secular equation is solved at the 89 points of the 1/48th of the Rrillouin zone. The density of states and partial density of states histograms are obtained. The populations of the orbitals show that about 0.5 electrons transfer from the carbon to the vanadium orbitals. However. the distribution of the electron rharge density points out that there are strong directional metalnon-metal bonds, in which carbon cannot be considered as a positive ion. Ha nepexoir, HMepHo 0,5 a n e~~p o~a c op611~anefi ymepona K MeTanny. OnHaI<o, I I~O C T -

Projected surface energy bands, Shockley surface states, and bonding in transition‐metal monocompounds with rock‐salt structure: Example of NbC

“…As mentioned in Sec. 1, the possibility cannot be excluded [26,27] that ligand-metal (sp,sp) HG exist, which would mean the presence of this type of bonds in the materials investigated. It follows from GR analysis that weak ( p , f2,) hybridization is present in transition-metal nitrides and oxides.…”

Average replicated T-matrix approximation: valence band of non-crystalline metallic alloys

“…Before applying (14) to the Lloyd formula (13) it might be necessary to show that the average T-matrix of the system under consideration with regard to optical theorem (5) can be represented by the following sequence…”

“…Both Hartree and exchange-correlation potentials are some functional of ρ α (r) i. e., the single-site density of electron gas. For the case of a disordered system, we find ρ α (r) within Mattheis method [11] used in a series of works [13,12,14] applying the partial PCF and according to its definition…”