mirror of
https://github.com/pfloos/quack
synced 2024-11-13 01:23:59 +01:00
132 lines
2.7 KiB
Fortran
132 lines
2.7 KiB
Fortran
subroutine UCC_lda_exchange_individual_energy(nEns,wEns,nCC,aCC,nGrid,weight,rhow,rho,Cx_choice,doNcentered,LZx,Ex)
|
|
|
|
|
|
! Compute the unrestricted version of the curvature-corrected exchange functional
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
integer,intent(in) :: nEns
|
|
double precision,intent(in) :: wEns(nEns)
|
|
integer,intent(in) :: nCC
|
|
double precision,intent(in) :: aCC(nCC,nEns-1)
|
|
integer,intent(in) :: nGrid
|
|
double precision,intent(in) :: weight(nGrid)
|
|
double precision,intent(in) :: rhow(nGrid,nspin)
|
|
double precision,intent(in) :: rho(nGrid,nspin,nEns)
|
|
integer,intent(in) :: Cx_choice
|
|
logical,intent(in) :: doNcentered
|
|
|
|
! Local variables
|
|
|
|
integer :: iG,iEns,ispin
|
|
double precision :: r,rI
|
|
double precision :: e,dedr
|
|
|
|
double precision :: a1,b1,c1,d1,w1
|
|
double precision :: a2,b2,c2,d2,w2
|
|
double precision :: Fx1,Fx2,Cx
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: LZx(nspin)
|
|
double precision,intent(out) :: Ex(nspin,nEns)
|
|
|
|
! Defining enhancements factor for weight-dependent functionals
|
|
|
|
if(doNcentered) then
|
|
|
|
! Parameters for first state
|
|
|
|
a1 = aCC(1,1)
|
|
b1 = aCC(2,1)
|
|
c1 = aCC(3,1)
|
|
d1 = aCC(4,1)
|
|
|
|
! Parameters for second state
|
|
|
|
a2 = aCC(1,2)
|
|
b2 = aCC(2,2)
|
|
c2 = aCC(3,2)
|
|
d2 = aCC(4,2)
|
|
|
|
w1 = wEns(2)
|
|
Fx1 = 1d0 + a1*w1 + b1*w1**2 + c1*w1**3 + d1*w1**4
|
|
|
|
w2 = wEns(3)
|
|
Fx2 = 1d0 + a2*w2 + b2*w2**2 + c2*w2**3 + d2*w2**4
|
|
|
|
else
|
|
|
|
! Parameters for first state
|
|
|
|
a1 = aCC(1,1)
|
|
b1 = aCC(2,1)
|
|
c1 = aCC(3,1)
|
|
|
|
! Parameters for second state
|
|
|
|
a2 = aCC(1,2)
|
|
b2 = aCC(2,2)
|
|
c2 = aCC(3,2)
|
|
|
|
w1 = wEns(2)
|
|
Fx1 = 1d0 - w1*(1d0 - w1)*(a1 + b1*(w1 - 0.5d0) + c1*(w1 - 0.5d0)**2)
|
|
|
|
w2 = wEns(3)
|
|
Fx2 = 1d0 - w2*(1d0 - w2)*(a2 + b2*(w2 - 0.5d0) + c2*(w2 - 0.5d0)**2)
|
|
|
|
endif
|
|
|
|
select case (Cx_choice)
|
|
|
|
case(1)
|
|
Cx = CxLSDA*Fx1
|
|
|
|
case(2)
|
|
Cx = CxLSDA*Fx2
|
|
|
|
case(3)
|
|
Cx = CxLSDA*Fx2*Fx1
|
|
|
|
case default
|
|
Cx = CxLSDA
|
|
|
|
end select
|
|
|
|
! Compute LDA exchange matrix in the AO basis
|
|
|
|
Ex(:,:) = 0d0
|
|
LZx(:) = 0d0
|
|
|
|
do ispin=1,nspin
|
|
|
|
do iG=1,nGrid
|
|
|
|
r = max(0d0,rhow(iG,ispin))
|
|
|
|
if(r > threshold) then
|
|
|
|
e = Cx*r**(+1d0/3d0)
|
|
dedr = 1d0/3d0*Cx*r**(-2d0/3d0)
|
|
|
|
LZx(ispin) = LZx(ispin) - weight(iG)*dedr*r*r
|
|
|
|
do iEns=1,nEns
|
|
|
|
rI = max(0d0,rho(iG,ispin,iEns))
|
|
|
|
if(rI > threshold) Ex(ispin,iEns) = Ex(ispin,iEns) + weight(iG)*(e+dedr*r)*rI
|
|
|
|
end do
|
|
|
|
endif
|
|
|
|
enddo
|
|
|
|
enddo
|
|
|
|
end subroutine UCC_lda_exchange_individual_energy
|