1(* 2 Copyright (C) 2017 M.A.L. Marques 3 4 This Source Code Form is subject to the terms of the Mozilla Public 5 License, v. 2.0. If a copy of the MPL was not distributed with this 6 file, You can obtain one at http://mozilla.org/MPL/2.0/. 7*) 8 9(* type: gga_exc *) 10 11$define lda_c_pw_params 12$include "lda_c_pw.mpl" 13 14pw91_C_c0 := 4.235e-3: 15pw91_alpha := 0.09: 16pw91_nu := 16/Pi * (3*Pi^2)^(1/3): 17pw91_beta := pw91_nu*pw91_C_c0: 18 19pw91_c1 := pw91_beta^2/(2*pw91_alpha): 20pw91_c2 := 2*pw91_alpha/pw91_beta: 21 22(* Equation (14) *) 23A := (rs, z) -> pw91_c2/(exp(-2*pw91_alpha*f_pw(rs, z)/(mphi(z)^3*pw91_beta^2)) - 1): 24 25(* Equation (13) *) 26H0 := (rs, z, t) -> pw91_c1*mphi(z)^3*log(1 27 + pw91_c2*(t^2 + A(rs, z)*t^4) / (1 + A(rs, z)*t^2 + A(rs, z)^2*t^4) 28): 29 30(* Pade parametrized form of C-xc found in 31 M Rasolt & DJW Geldart, Phys. Rev. B 34, 1325 (1986) 32*) 33RS_a := [2.568, 23.266, 0.007389]: 34RS_b := [1, 8.723, 0.472]: 35RG_C_xc := rs -> (RS_a[1] + RS_a[2]*rs + RS_a[3]*rs^2)/(1000*(RS_b[1] + RS_b[2]*rs + RS_b[3]*rs^2)): 36 37(* Equation (15) *) 38C_xc0 := 2.568e-3: 39C_x := -0.001667: 40h_a1 := -100 * 4/Pi * (4/(9*Pi))^(1/3): 41 42H1 := (rs, z, t) -> pw91_nu * (RG_C_xc(rs) - C_xc0 - 3*C_x/7) 43 * mphi(z)^3*t^2*exp(h_a1*rs*mphi(z)^4*t^2): 44 45f_pw91 := (rs, z, xt, xs0, xs1) -> 46 f_pw(rs, z) + H0(rs, z, tt(rs, z, xt)) + H1(rs, z, tt(rs, z, xt)): 47f := (rs, z, xt, xs0, xs1) -> f_pw91(rs, z, xt, xs0, xs1): 48