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arXiv · 2208.07729

Exchange torque in noncollinear spin density functional theory with a semilocal exchange functional

Nicolas Tancogne-Dejean·Angel Rubio·Carsten A. Ullrich
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Abstract

We present a semilocal exchange-correlation energy functional for noncollinear spin density functional theory based on short-range expansions of the spin-resolved exchange hole and the two-body density matrix. Our functional is explicitly derived for noncollinear magnetism, U(1) and SU(2) gauge invariant, and gives rise to nonvanishing exchange-correlation torques. Testing the functional for frustrated antiferromagnetic chromium clusters, the exchange part is shown to perform favorably compared to the far more expensive Slater and optimized effective potentials, and a delicate interplay between exchange and correlation torques is uncovered.

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Nicolas Tancogne-Dejean, Angel Rubio, Carsten A. Ullrich. 2023-03-17. Exchange torque in noncollinear spin density functional theory with a semilocal exchange functional. https://doi.org/10.1103/physrevb.107.165111

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