Alternative separation of exchange and correlation in density-functional theory.

Journal Article · Sat Feb 01 04:00:00 EST 2003 · Proposed for publication in Physical Review Letters.

DOI:https://doi.org/10.1103/PhysRevB.68.245120· OSTI ID:917444

Armiento, Rickard Roberto ^[1]; Mattsson, Ann Elisabet

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1. Royal Institute of Technology, AlbaNova University Center, Stockholm, Sweden

It has recently been shown that local values of the conventional exchange energy per particle cannot be described by an analytic expansion in the density variation. Yet, it is known that the total exchange-correlation (XC) energy per particle does not show any corresponding nonanalyticity. Indeed, the nonanalyticity is here shown to be an effect of the separation into conventional exchange and correlation. We construct an alternative separation in which the exchange part is made well behaved by screening its long-ranged contributions, and the correlation part is adjusted accordingly. This alternative separation is as valid as the conventional one, and introduces no new approximations to the total XC energy. We demonstrate functional development based on this approach by creating and deploying a local-density-approximation-type XC functional. Hence, this work includes both the theory and the practical calculations needed to provide a starting point for an alternative approach towards improved approximations of the total XC energy.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 917444
• Report Number(s): SAND2003-0902J
• Journal Information: Proposed for publication in Physical Review Letters., Journal Name: Proposed for publication in Physical Review Letters.
• Country of Publication: United States
• Language: English

Related Subjects

97 MATHEMATICS AND COMPUTING
99 GENERAL AND MISCELLANEOUS
APPROXIMATIONS
CORRELATIONS
DENSITY FUNCTIONAL METHOD
ENERGY TRANSFER
PARTICLES