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Title: Green's function multiple-scattering theory with a truncated basis set: An augmented-KKR formalism

Korringa-Kohn-Rostoker (KKR) Green's function, multiple-scattering theory is an ecient sitecentered, electronic-structure technique for addressing an assembly of N scatterers. Wave-functions are expanded in a spherical-wave basis on each scattering center and indexed up to a maximum orbital and azimuthal number L max = (l,m) max, while scattering matrices, which determine spectral properties, are truncated at L tr = (l,m) tr where phase shifts δl>l tr are negligible. Historically, L max is set equal to L tr, which is correct for large enough L max but not computationally expedient; a better procedure retains higher-order (free-electron and single-site) contributions for L max > L tr with δl>l tr set to zero [Zhang and Butler, Phys. Rev. B 46, 7433]. We present a numerically ecient and accurate augmented-KKR Green's function formalism that solves the KKR equations by exact matrix inversion [R 3 process with rank N(l tr + 1) 2] and includes higher-L contributions via linear algebra [R 2 process with rank N(l max +1) 2]. Augmented-KKR approach yields properly normalized wave-functions, numerically cheaper basis-set convergence, and a total charge density and electron count that agrees with Lloyd's formula. We apply our formalism to fcc Cu, bcc Fe and L1 0 CoPt, andmore » present the numerical results for accuracy and for the convergence of the total energies, Fermi energies, and magnetic moments versus L max for a given L tr.« less
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [4]
  1. Indian Inst. of Technology (IIT), Mumbai (India). Dept. of Physics
  2. Ames Lab., Ames, IA (United States). Division of Materials Science & Engineering
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Ames Lab., Ames, IA (United States). Division of Materials Science & Engineering; Iowa State Univ., Ames, IA (United States). Dept. of Materials Science & Engineering
Publication Date:
Grant/Contract Number:
AC05-00OR22725; FG02-03ER46026; AC02- 07CH11358; 13IRCCSG020; AC02-07CH11358
Type:
Accepted Manuscript
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 90; Journal Issue: 20; Journal ID: ISSN 1098-0121
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Korringa-Kohn-Rostoker (KKR) Green's function; multiple-scattering
OSTI Identifier:
1286786
Alternate Identifier(s):
OSTI ID: 1180863