Title




Slater's nonlocal exchange potential and beyond
 
Author




 
Abstract




The local density approximation (LDA) to the exchange potential Vx(r), namely the rho(1/3) electron gas form, was already transcended in Slater's 1951 paper. Here, using Dirac's 1930 form for the exchange energy density epsilon(x)(r), the Slater (SI) nonlocal exchange potential Vx(sl)(r) is defined by 2epsilon(x)(r)/rho(r). In spherical atomic ions, say the Be or Nelike series, this form already has the correct behavior in both r > 0 and r > infinity limits when known properties of the exchange energy density E,(r) and the groundstate electron density rho(r) are invoked. As examples, some emphasis will first be given to the use of the socalled 1/Z expansion in such spherical atomic ions, for which analytic results can be obtained for both epsilon(x)(r) and rho(r) as the atomic number Z becomes large. The usefulness of the 1/Z expansion is directly demonstrated for the U atomic ion with 18 electrons by comparison with the optimized effective potential prediction. A rather general integral equation for the exchange potential is then proposed. Finally, without appeal to large Z, twolevel systems are considered, with specific reference to the Be atom and to the LiH molecule. In all cases treated, the Slater potential Vx(sl)(r) is a valuable starting point, even though it needs appreciable quantitative corrections reflecting directly atomic shell structure. (C) 2004 Wiley Periodicals, Inc. Int J Quantum Chem 102: 6471, 2005. 
 
Language




English
 
Source (journal)




International journal of quantum chemistry.  New York, N.Y.
 
Publication




New York, N.Y.
:
2005
 
ISSN




00207608
 
Volume/pages




102
:1
(2005)
, p. 6471
 
ISI




000227015600007
 
Full text (Publisher's DOI)




 
Full text (open access)




 
