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mirror of https://github.com/pfloos/quack synced 2024-12-25 13:53:41 +01:00
QuAcK/src/eDFT/UPBE_gga_correlation_potential.f90
2021-03-01 15:01:47 +01:00

89 lines
2.7 KiB
Fortran

subroutine UPBE_gga_correlation_potential(nGrid,weight,nBas,AO,dAO,rho,drho,Fc)
! Compute LYP correlation potential
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: nGrid
double precision,intent(in) :: weight(nGrid)
integer,intent(in) :: nBas
double precision,intent(in) :: AO(nBas,nGrid)
double precision,intent(in) :: dAO(ncart,nBas,nGrid)
double precision,intent(in) :: rho(nGrid,nspin)
double precision,intent(in) :: drho(ncart,nGrid,nspin)
! Local variables
integer :: mu,nu,iG
double precision :: vAO,gaAO,gbAO
double precision :: ra,rb,r
double precision :: ga,gab,gb,g
double precision :: dfdra,dfdrb
double precision :: dfdga,dfdgab,dfdgb
double precision :: dodra,dodrb,dddra,dddrb
double precision :: a,b,c,d
double precision :: Cf,omega,delta
! Output variables
double precision,intent(out) :: Fc(nBas,nBas,nspin)
! Prameter of the functional
! Compute matrix elements in the AO basis
call UPW92_lda_correlation_potential(nGrid,weight,nBas,AO,rho,Fc)
do mu=1,nBas
do nu=1,nBas
do iG=1,nGrid
ra = max(0d0,rho(iG,1))
rb = max(0d0,rho(iG,2))
r = ra + rb
if(r > threshold) then
ga = drho(1,iG,1)*drho(1,iG,1) + drho(2,iG,1)*drho(2,iG,1) + drho(3,iG,1)*drho(3,iG,1)
gb = drho(1,iG,2)*drho(1,iG,2) + drho(2,iG,2)*drho(2,iG,2) + drho(3,iG,2)*drho(3,iG,2)
gab = drho(1,iG,1)*drho(1,iG,2) + drho(2,iG,1)*drho(2,iG,2) + drho(3,iG,1)*drho(3,iG,2)
g = ga + 2d0*gab + gb
vAO = weight(iG)*AO(mu,iG)*AO(nu,iG)
dfdra = 0d0
dfdrb = 0d0
Fc(mu,nu,1) = Fc(mu,nu,1) + vAO*dfdra
Fc(mu,nu,2) = Fc(mu,nu,2) + vAO*dfdrb
gaAO = drho(1,iG,1)*(dAO(1,mu,iG)*AO(nu,iG) + AO(mu,iG)*dAO(1,nu,iG)) &
+ drho(2,iG,1)*(dAO(2,mu,iG)*AO(nu,iG) + AO(mu,iG)*dAO(2,nu,iG)) &
+ drho(3,iG,1)*(dAO(3,mu,iG)*AO(nu,iG) + AO(mu,iG)*dAO(3,nu,iG))
gaAO = weight(iG)*gaAO
gbAO = drho(1,iG,2)*(dAO(1,mu,iG)*AO(nu,iG) + AO(mu,iG)*dAO(1,nu,iG)) &
+ drho(2,iG,2)*(dAO(2,mu,iG)*AO(nu,iG) + AO(mu,iG)*dAO(2,nu,iG)) &
+ drho(3,iG,2)*(dAO(3,mu,iG)*AO(nu,iG) + AO(mu,iG)*dAO(3,nu,iG))
gbAO = weight(iG)*gbAO
dfdga = 0d0
dfdgab = 0d0
dfdgb = 0d0
Fc(mu,nu,1) = Fc(mu,nu,1) + 2d0*gaAO*dfdga + gbAO*dfdgab
Fc(mu,nu,2) = Fc(mu,nu,2) + 2d0*gbAO*dfdgb + gaAO*dfdgab
end if
end do
end do
end do
end subroutine UPBE_gga_correlation_potential