Giant density-of-states van Hove singularities in the face-centered cubic lattice

Abstract

All van Hove singularities in the density of states (DOS) of face-centered cubic lattice in the nearest and next-nearest neighbor approximation, focusing on higher-order ones, are found and classified. At special values of the ratio τ of nearest (t) and next-nearest neighbor hopping integral t′ giant DOS singularities, caused by van Hove lines or surfaces, are formed. An exact formula for DOS which provides efficient numerical implementation is proposed. The standard tetrahedron method is demonstrated to be inapplicable due to its poor convergence in the vicinity of kinks caused by van Hove singularities. A comparison with the case of large space dimensionality (infinite coordination number) including next-nearest neighbors is performed.