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quack/src/eDFT/GOK_RKS.f90

349 lines
10 KiB
Fortran

subroutine GOK_RKS(restart,x_rung,x_DFA,c_rung,c_DFA,LDA_centered,nEns,wEns,nGrid,weight,maxSCF,thresh, &
max_diis,guess_type,nBas,AO,dAO,nO,nV,S,T,V,Hc,ERI,X,ENuc,Ew,EwGIC,c)
! Perform restricted Kohn-Sham calculation for ensembles
implicit none
include 'parameters.h'
! Input variables
logical,intent(in) :: restart
integer,intent(in) :: x_rung,c_rung
character(len=12),intent(in) :: x_DFA,c_DFA
logical,intent(in) :: LDA_centered
integer,intent(in) :: nEns
double precision,intent(in) :: wEns(nEns)
integer,intent(in) :: nGrid
double precision,intent(in) :: weight(nGrid)
integer,intent(in) :: maxSCF
integer,intent(in) :: max_diis
integer,intent(in) :: guess_type
double precision,intent(in) :: thresh
integer,intent(in) :: nBas
double precision,intent(in) :: AO(nBas,nGrid)
double precision,intent(in) :: dAO(ncart,nBas,nGrid)
integer,intent(in) :: nO
integer,intent(in) :: nV
double precision,intent(in) :: S(nBas,nBas)
double precision,intent(in) :: T(nBas,nBas)
double precision,intent(in) :: V(nBas,nBas)
double precision,intent(in) :: Hc(nBas,nBas)
double precision,intent(in) :: X(nBas,nBas)
double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
double precision,intent(in) :: ENuc
double precision,intent(inout):: c(nBas,nBas)
! Local variables
integer :: xc_rung
integer :: nSCF,nBasSq
integer :: n_diis
double precision :: conv
double precision :: rcond
double precision :: ET
double precision :: EV
double precision :: EJ
double precision :: Ex
double precision :: Ec
double precision,allocatable :: eps(:)
double precision,allocatable :: cp(:,:)
double precision,allocatable :: J(:,:)
double precision,allocatable :: F(:,:)
double precision,allocatable :: Fp(:,:)
double precision,allocatable :: Fx(:,:)
double precision,allocatable :: FxHF(:,:)
double precision,allocatable :: Fc(:,:)
double precision,allocatable :: err(:,:)
double precision,allocatable :: err_diis(:,:)
double precision,allocatable :: F_diis(:,:)
double precision,external :: trace_matrix
double precision,external :: electron_number
double precision,allocatable :: Pw(:,:)
double precision,allocatable :: rhow(:)
double precision,allocatable :: drhow(:,:)
double precision :: nEl
double precision,allocatable :: P(:,:,:)
double precision,allocatable :: rho(:,:)
double precision,allocatable :: drho(:,:,:)
double precision :: E(nEns)
double precision :: Om(nEns)
integer :: iEns
! Output variables
double precision,intent(out) :: Ew
double precision,intent(out) :: EwGIC
! Hello world
write(*,*)
write(*,*)'************************************************'
write(*,*)'* Restricted Kohn-Sham calculation *'
write(*,*)'* *** for ensembles *** *'
write(*,*)'************************************************'
write(*,*)
! Useful stuff
nBasSq = nBas*nBas
!------------------------------------------------------------------------
! Rung of Jacob's ladder
!------------------------------------------------------------------------
! Select rung for exchange
write(*,*)
write(*,*) '*******************************************************************'
write(*,*) '* EXCHANGE RUNG *'
write(*,*) '*******************************************************************'
call select_rung(x_rung,x_DFA)
! Select rung for correlation
write(*,*)
write(*,*) '*******************************************************************'
write(*,*) '* CORRELATION RUNG *'
write(*,*) '*******************************************************************'
call select_rung(c_rung,c_DFA)
! Overall rung
xc_rung = max(x_rung,c_rung)
! Memory allocation
allocate(eps(nBas),cp(nBas,nBas),J(nBas,nBas), &
F(nBas,nBas),Fp(nBas,nBas),Fx(nBas,nBas), &
FxHF(nBas,nBas),Fc(nBas,nBas),err(nBas,nBas), &
Pw(nBas,nBas),rhow(nGrid),drhow(ncart,nGrid), &
err_diis(nBasSq,max_diis),F_diis(nBasSq,max_diis), &
P(nBas,nBas,nEns),rho(nGrid,nEns),drho(ncart,nGrid,nEns))
! Guess coefficients and eigenvalues
if(.not. restart) then
! call mo_guess(nBas,nO,guess_type,S,Hc,ERI,J,Fx,X,cp,F,Fp,eps,c,P)
if(guess_type == 1) then
cp(:,:) = matmul(transpose(X(:,:)),matmul(Hc(:,:),X(:,:)))
call diagonalize_matrix(nBas,cp(:,:),eps(:))
c(:,:) = matmul(X(:,:),cp(:,:))
else
print*,'Wrong guess option'
stop
end if
end if
! Initialization
nSCF = 0
conv = 1d0
nEl = 0d0
Ex = 0d0
Ec = 0d0
Fx(:,:) = 0d0
FxHF(:,:) = 0d0
Fc(:,:) = 0d0
n_diis = 0
F_diis(:,:) = 0d0
err_diis(:,:) = 0d0
!------------------------------------------------------------------------
! Main SCF loop
!------------------------------------------------------------------------
write(*,*)
write(*,*)'------------------------------------------------------------------------------------------'
write(*,'(1X,A1,1X,A3,1X,A1,1X,A16,1X,A1,1X,A16,1X,A1,1X,A16,1X,A1,1X,A10,1X,A1,1X,A10,1X,A1,1X)') &
'|','#','|','E(KS)','|','Ex(KS)','|','Ec(KS)','|','Conv','|','nEl','|'
write(*,*)'------------------------------------------------------------------------------------------'
do while(conv > thresh .and. nSCF < maxSCF)
! Increment
nSCF = nSCF + 1
!------------------------------------------------------------------------
! Compute density matrix
!------------------------------------------------------------------------
call restricted_density_matrix(nBas,nEns,nO,c(:,:),P(:,:,:))
! Weight-dependent density matrix
Pw(:,:) = 0d0
do iEns=1,nEns
Pw(:,:) = Pw(:,:) + wEns(iEns)*P(:,:,iEns)
end do
!------------------------------------------------------------------------
! Compute one-electron density and its gradient if necessary
!------------------------------------------------------------------------
do iEns=1,nEns
call density(nGrid,nBas,P(:,:,iEns),AO(:,:),rho(:,iEns))
end do
! Weight-dependent one-electron density
rhow(:) = 0d0
do iEns=1,nEns
rhow(:) = rhow(:) + wEns(iEns)*rho(:,iEns)
end do
if(xc_rung > 1) then
! Compute gradient of the one-electron density
do iEns=1,nEns
call gradient_density(nGrid,nBas,P(:,:,iEns),AO(:,:),dAO(:,:,:),drho(:,:,iEns))
end do
! Weight-dependent one-electron density gradient
drhow(:,:) = 0d0
do iEns=1,nEns
drhow(:,:) = drhow(:,:) + wEns(iEns)*drho(:,:,iEns)
end do
end if
! Build Coulomb repulsion
call hartree_coulomb(nBas,Pw(:,:),ERI(:,:,:,:),J(:,:))
! Compute exchange potential
call exchange_potential(x_rung,x_DFA,LDA_centered,nEns,wEns(:),nGrid,weight(:),nBas,Pw(:,:),ERI(:,:,:,:), &
AO(:,:),dAO(:,:,:),rhow(:),drhow(:,:),Fx(:,:),FxHF(:,:))
! Compute correlation potential
call restricted_correlation_potential(c_rung,c_DFA,LDA_centered,nEns,wEns(:),nGrid,weight(:), &
nBas,AO(:,:),dAO(:,:,:),rhow(:),drhow(:,:),Fc(:,:))
! Build Fock operator
F(:,:) = Hc(:,:) + J(:,:) + Fx(:,:) + Fc(:,:)
! Check convergence
err(:,:) = matmul(F(:,:),matmul(Pw(:,:),S(:,:))) - matmul(matmul(S(:,:),Pw(:,:)),F(:,:))
conv = maxval(abs(err(:,:)))
! DIIS extrapolation
n_diis = min(n_diis+1,max_diis)
call DIIS_extrapolation(rcond,nBasSq,nBasSq,n_diis,err_diis(:,:),F_diis(:,:),err(:,:),F(:,:))
! Reset DIIS if required
if(abs(rcond) < 1d-15) n_diis = 0
! Transform Fock matrix in orthogonal basis
Fp(:,:) = matmul(transpose(X(:,:)),matmul(F(:,:),X(:,:)))
! Diagonalize Fock matrix to get eigenvectors and eigenvalues
cp(:,:) = Fp(:,:)
call diagonalize_matrix(nBas,cp(:,:),eps(:))
! Back-transform eigenvectors in non-orthogonal basis
c(:,:) = matmul(X(:,:),cp(:,:))
!------------------------------------------------------------------------
! Compute KS energy
!------------------------------------------------------------------------
! Kinetic energy
ET = trace_matrix(nBas,matmul(Pw(:,:),T(:,:)))
! Potential energy
EV = trace_matrix(nBas,matmul(Pw(:,:),V(:,:)))
! Coulomb energy
EJ = 0.5d0*trace_matrix(nBas,matmul(Pw(:,:),J(:,:)))
! Exchange energy
call exchange_energy(x_rung,x_DFA,LDA_centered,nEns,wEns(:),nGrid,weight(:),nBas, &
Pw(:,:),FxHF(:,:),rhow(:),drhow(:,:),Ex)
! Correlation energy
call restricted_correlation_energy(c_rung,c_DFA,LDA_centered,nEns,wEns(:),nGrid,weight(:),rhow(:),drhow(:,:),Ec)
! Total energy
Ew = ET + EV + EJ + Ex + Ec
! Check the grid accuracy by computing the number of electrons
nEl = electron_number(nGrid,weight(:),rhow(:))
! Dump results
write(*,'(1X,A1,1X,I3,1X,A1,1X,F16.10,1X,A1,1X,F16.10,1X,A1,1X,F16.10,1X,A1,1X,F10.6,1X,A1,1X,F10.6,1X,A1,1X)') &
'|',nSCF,'|',Ew + ENuc,'|',Ex,'|',Ec,'|',conv,'|',nEl,'|'
end do
write(*,*)'------------------------------------------------------------------------------------------'
!------------------------------------------------------------------------
! End of SCF loop
!------------------------------------------------------------------------
! Did it actually converge?
if(nSCF == maxSCF) then
write(*,*)
write(*,*)'!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!'
write(*,*)' Convergence failed '
write(*,*)'!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!'
write(*,*)
stop
end if
! Compute final KS energy
call print_RKS(nBas,nO,eps(:),c(:,:),ENuc,ET,EV,EJ,Ex,Ec,Ew)
!------------------------------------------------------------------------
! Compute individual energies from ensemble energy
!------------------------------------------------------------------------
call restricted_individual_energy(x_rung,x_DFA,c_rung,c_DFA,LDA_centered,nEns,wEns(:),nGrid,weight(:), &
nBas,nO,nV,T(:,:),V(:,:),ERI(:,:,:,:),ENuc,eps(:),Pw(:,:),rhow(:),drhow(:,:), &
J(:,:),P(:,:,:),rho(:,:),drho(:,:,:),Ew,EwGIC,E(:),Om(:))
end subroutine GOK_RKS