Premium
Comparison of different approaches to the study of local defects in crystals. II. Substitutional impurities in the tight‐binding approximation
Author(s) -
Pisani C.,
Dovesi R.,
Ugliengo P.
Publication year - 1983
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221160216
Subject(s) - cluster (spacecraft) , impurity , tight binding , embedding , operator (biology) , coupled cluster , coupling (piping) , molecular physics , chemistry , physics , condensed matter physics , statistical physics , electronic structure , materials science , computational chemistry , computer science , quantum mechanics , molecule , artificial intelligence , transcription factor , biochemistry , repressor , metallurgy , gene , programming language
Different approaches to the study of local defects in perfect crystals are compared as applied to the classical problem of substitutional impurities in tight binding (TB) cubic metals. The standard embedding procedure proposed by Koster and Slater (KS) is perfectly suited for this problem and its results are taken as a reference. It is so possible to evaluate the performance of isolated cluster (IC) calculations, and of those “perturbed cluster” approaches which correct the cluster molecular solution by a suitable coupling operator (MLEC schemes). It is shown that while IC results are affected by enormous relative errors at small perturbations even with large clusters, the MLEC approach is very effective in accounting for the presence of the surrounding media and reproducing the correct electronic structure within the cluster.