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qp2/plugins/local/non_h_ints_mu/pot_j_gauss.irp.f
2024-09-05 22:01:22 +02:00

147 lines
4.3 KiB
Fortran

double precision function j_simple(x,mu)
implicit none
double precision, intent(in) :: x,mu
double precision :: j_mu_simple,j_gauss_simple
if(j2e_type .eq. "Mu".or.j2e_type .eq. "Mur") then
j_simple = j_mu_simple(x,mu)
else if(j2e_type .eq. "Mugauss".or.j2e_type .eq. "Murgauss") then
j_simple = j_gauss_simple(x,mu) + j_mu_simple(x,mu)
endif
end
double precision function j_mu_simple(x,mu)
implicit none
double precision, intent(in):: x,mu
include 'constants.include.F'
BEGIN_DOC
! j_mu(mu,x) = 0.5 x (1 - erf(mu x)) - 1/[2 sqrt(pi)mu] exp(-(x*mu)^2)
END_DOC
j_mu_simple = 0.5d0 * x * (1.D0 - derf(mu*x)) - 0.5d0 * inv_sq_pi/mu * dexp(-x*mu*x*mu)
end
double precision function j_gauss_simple(x,mu)
implicit none
double precision, intent(in):: x,mu
include 'constants.include.F'
BEGIN_DOC
! j_mu(mu,x) = c/[4 alpha^2 mu] exp(-(alpha * mu * x)^2)
! with c = 27/(8 sqrt(pi)), alpha=3/2
END_DOC
double precision :: x_tmp
x_tmp = alpha_mu_gauss * mu * x
j_gauss_simple = 0.25d0 * c_mu_gauss / (alpha_mu_gauss*alpha_mu_gauss*mu) * dexp(-x_tmp*x_tmp)
end
double precision function j_mu_deriv(x,mu)
implicit none
BEGIN_DOC
! d/dx j_mu(mu,x) = d/dx 0.5 x (1 - erf(mu x)) - 1/[2 sqrt(pi)mu] exp(-(x*mu)^2)
! = 0.5*(1 - erf(mu x))
END_DOC
include 'constants.include.F'
double precision, intent(in) :: x,mu
j_mu_deriv = 0.5d0 * (1.d0 - derf(mu*x))
end
double precision function j_mu_deriv_2(x,mu)
implicit none
BEGIN_DOC
! d^2/dx^2 j_mu(mu,x) = d^2/dx^2 0.5 x (1 - erf(mu x)) - 1/[2 sqrt(pi)mu] exp(-(x*mu)^2)
! = -mu/sqrt(pi) * exp(-(mu x)^2)
END_DOC
include 'constants.include.F'
double precision, intent(in) :: x,mu
j_mu_deriv_2 = - mu * inv_sq_pi * dexp(-x*mu*x*mu)
end
double precision function j_gauss_deriv(x,mu)
implicit none
include 'constants.include.F'
double precision, intent(in) :: x,mu
BEGIN_DOC
! d/dx j_gauss(mu,x) = d/dx c/[4 alpha^2 mu] exp(-(alpha * mu * x)^2)
! with c = 27/(8 sqrt(pi)), alpha=3/2
! = -0.5 * mu * c * x * exp(-(alpha * mu * x)^2)
END_DOC
double precision :: x_tmp
x_tmp = alpha_mu_gauss * mu * x
j_gauss_deriv = -0.5d0 * mu * c_mu_gauss * x * exp(-x_tmp*x_tmp)
end
double precision function j_gauss_deriv_2(x,mu)
implicit none
include 'constants.include.F'
double precision, intent(in) :: x,mu
BEGIN_DOC
! d/dx j_gauss(mu,x) = d/dx c/[4 alpha^2 mu] exp(-(alpha * mu * x)^2)
! with c = 27/(8 sqrt(pi)), alpha=3/2
! = 0.5 * mu * c * exp(-(alpha * mu * x)^2) * (2 (alpha*mu*x)^2 - 1)
END_DOC
double precision :: x_tmp
x_tmp = alpha_mu_gauss * mu * x
x_tmp = x_tmp * x_tmp
j_gauss_deriv_2 = 0.5d0 * mu * c_mu_gauss * exp(-x_tmp) * (2.d0*x_tmp - 1.d0)
end
double precision function j_erf_gauss_deriv(x,mu)
implicit none
double precision, intent(in) :: x,mu
BEGIN_DOC
! d/dx (j_gauss(mu,x)+j_mu(mu,x))
END_DOC
double precision :: j_gauss_deriv,j_mu_deriv
j_erf_gauss_deriv = j_gauss_deriv(x,mu)+j_mu_deriv(x,mu)
end
double precision function j_erf_gauss_deriv_2(x,mu)
implicit none
double precision, intent(in) :: x,mu
BEGIN_DOC
! d^2/dx^2 (j_gauss(mu,x)+j_mu(mu,x))
END_DOC
double precision :: j_gauss_deriv_2,j_mu_deriv_2
j_erf_gauss_deriv_2 = j_gauss_deriv_2(x,mu)+j_mu_deriv_2(x,mu)
end
double precision function pot_j_gauss(x,mu)
implicit none
double precision, intent(in) :: x,mu
BEGIN_DOC
! effective scalar potential associated with the erf_gauss correlation factor
!
! 1/x( 1 - 2 * d/dx j_erf_gauss(x,mu)) - d^2/dx^2 j_erf_gauss(x,mu)) - d/dx d/dx (j_erf_gauss(x,mu))^2
END_DOC
double precision :: j_erf_gauss_deriv_2,j_erf_gauss_deriv
double precision :: deriv_1, deriv_2
pot_j_gauss = 0.d0
if(x.ne.0.d0)then
deriv_1 = j_erf_gauss_deriv(x,mu)
deriv_2 = j_erf_gauss_deriv_2(x,mu)
pot_j_gauss = 1.d0/x * (1.d0 - 2.d0 * deriv_1) - deriv_1 * deriv_1 - deriv_2
endif
end
double precision function pot_j_mu(x,mu)
implicit none
double precision, intent(in) :: x,mu
BEGIN_DOC
! effective scalar potential associated with the correlation factor
!
! 1/x( 1 - 2 * d/dx j_erf(x,mu)) - d^2/dx^2 j_erf(x,mu)) - d/dx d/dx (j_erf(x,mu))^2
END_DOC
double precision :: j_mu_deriv_2,j_mu_deriv
double precision :: deriv_1, deriv_2
pot_j_mu = 0.d0
if(x.ne.0.d0)then
deriv_1 = j_mu_deriv(x,mu)
deriv_2 = j_mu_deriv_2(x,mu)
pot_j_mu= 1.d0/x * (1.d0 - 2.d0 * deriv_1) - deriv_1 * deriv_1 - deriv_2
endif
end