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quack/src/eDFT/unrestricted_exchange_energy.f90

88 lines
2.2 KiB
Fortran

subroutine unrestricted_exchange_energy(rung,DFA,LDA_centered,nEns,wEns,aCC_w1,aCC_w2,nGrid,weight,nBas,P,FxHF, &
rho,drho,Ex,Cx_choice)
! Compute the exchange energy
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: rung
character(len=12),intent(in) :: DFA
logical,intent(in) :: LDA_centered
integer,intent(in) :: nEns
double precision,intent(in) :: wEns(nEns)
double precision,intent(in) :: aCC_w1(3)
double precision,intent(in) :: aCC_w2(3)
integer,intent(in) :: nGrid
double precision,intent(in) :: weight(nGrid)
integer,intent(in) :: nBas
double precision,intent(in) :: P(nBas,nBas)
double precision,intent(in) :: FxHF(nBas,nBas)
double precision,intent(in) :: rho(nGrid)
double precision,intent(in) :: drho(ncart,nGrid)
integer,intent(in) :: Cx_choice
! Local variables
double precision :: ExLDA,ExGGA,ExMGGA,ExHF
double precision :: cX,aX,aC
! Output variables
double precision,intent(out) :: Ex
select case (rung)
! Hartree calculation
case(0)
Ex = 0d0
! LDA functionals
case(1)
call unrestricted_lda_exchange_energy(DFA,LDA_centered,nEns,wEns,aCC_w1,aCC_w2,nGrid,weight,&
rho,ExLDA,Cx_choice)
Ex = ExLDA
! GGA functionals
case(2)
call unrestricted_gga_exchange_energy(DFA,nEns,wEns,nGrid,weight,rho,drho,ExGGA)
Ex = ExGGA
! MGGA functionals
case(3)
call unrestricted_mgga_exchange_energy(DFA,nEns,wEns,nGrid,weight,rho,drho,ExMGGA)
Ex = ExMGGA
! Hybrid functionals
case(4)
cX = 0.20d0
aX = 0.72d0
aC = 0.81d0
call unrestricted_lda_exchange_energy(DFA,nEns,wEns,nGrid,weight,rho,ExLDA,Cx_choice)
call unrestricted_gga_exchange_energy(DFA,nEns,wEns,nGrid,weight,rho,drho,ExGGA)
call unrestricted_fock_exchange_energy(nBas,P,FxHF,ExHF)
Ex = ExLDA &
+ cX*(ExHF - ExLDA) &
+ aX*(ExGGA - ExLDA)
end select
end subroutine unrestricted_exchange_energy