CORRELATION HOLE OF THE SPIN-POLARIZED ELECTRON-GAS, WITH EXACT SMALL-WAVE-VECTOR AND HIGH-DENSITY SCALING
CORRELATION HOLE OF THE SPIN-POLARIZED ELECTRON-GAS, WITH EXACT SMALL-WAVE-VECTOR AND HIGH-DENSITY SCALING
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DOI:
10.1103/physrevb.44.13298
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发表时间:
1991-12-15
影响因子:
3.7
通讯作者:
PERDEW, JP
中科院分区:
文献类型:
--
作者:
WANG, Y;PERDEW, JP
For a uniform electron gas of density n = n up + n down = 3/4-pi-r(s)3 = pi-k(s)6/192 and spin polarization zeta = (n up - n down)/n, we study the Fourier transform rho(c)BAR(k,r(s),zeta) of the correlation hole, as well as the correlation energy epsilon(c)(r(s),zeta) = integral-0/infinity dk rho(c)BAR/pi. In the high-density (r(s) --> 0) limit, we find a simple scaling relation k(s)rho(c)BAR/pi-g2 --> f(z,zeta), where z = k/gk(s), g = [(1 + zeta)2/3 + (1 - zeta)2/3]/2, and f(z,1) = f(z,0). The function f(z,zeta) is only weakly zeta dependent, and its small-z expansion - 3z/pi(2) + 4 square-root 3z2/pi(2) + ... is also the exact small-wave-vector (k --> 0) expansion for any r(s) or zeta. Motivated by these considerations, and by a discussion of the large-wave-vector and low-density limits, we present two Pade representations for rho(c)BAR at any k, r(s), or zeta, one within and one beyond the random-phase approximation (RPA). We also show that rho(c)RPABAR obeys a generalization of Misawa's spin-scaling relation for epsilon(c)RPA, and that the low-density (r(s) --> infinity) limit of epsilon(c)RPA is approximately r(s)-3/4.