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mirror of https://github.com/pfloos/quack synced 2024-11-09 15:43:56 +01:00
quack/src/HF/RHF.f90

210 lines
5.7 KiB
Fortran

subroutine RHF(maxSCF,thresh,max_diis,guess_type,nNuc,ZNuc,rNuc,ENuc,nBas,nO,S,T,V,Hc,ERI,dipole_int,X,ERHF,e,c,P,Vx)
! Perform restricted Hartree-Fock calculation
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: maxSCF,max_diis,guess_type
double precision,intent(in) :: thresh
integer,intent(in) :: nBas
integer,intent(in) :: nO
integer,intent(in) :: nNuc
double precision,intent(in) :: ZNuc(nNuc)
double precision,intent(in) :: rNuc(nNuc,ncart)
double precision,intent(in) :: ENuc
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) :: dipole_int(nBas,nBas,ncart)
! Local variables
integer :: nSCF
integer :: nBasSq
integer :: n_diis
double precision :: ET
double precision :: EV
double precision :: EJ
double precision :: EK
double precision :: dipole(ncart)
double precision :: Conv
double precision :: Gap
double precision :: rcond
double precision,external :: trace_matrix
double precision,allocatable :: error(:,:)
double precision,allocatable :: error_diis(:,:)
double precision,allocatable :: F_diis(:,:)
double precision,allocatable :: J(:,:)
double precision,allocatable :: K(:,:)
double precision,allocatable :: cp(:,:)
double precision,allocatable :: F(:,:)
double precision,allocatable :: Fp(:,:)
double precision,allocatable :: ON(:)
! Output variables
double precision,intent(out) :: ERHF
double precision,intent(out) :: e(nBas)
double precision,intent(out) :: c(nBas,nBas)
double precision,intent(out) :: P(nBas,nBas)
double precision,intent(out) :: Vx(nBas)
! Hello world
write(*,*)
write(*,*)'************************************************'
write(*,*)'| Restricted Hartree-Fock calculation |'
write(*,*)'************************************************'
write(*,*)
! Useful quantities
nBasSq = nBas*nBas
! Memory allocation
allocate(J(nBas,nBas),K(nBas,nBas),error(nBas,nBas), &
cp(nBas,nBas),Fp(nBas,nBas),F(nBas,nBas),ON(nBas), &
error_diis(nBasSq,max_diis),F_diis(nBasSq,max_diis))
! Guess coefficients and eigenvalues
call mo_guess(nBas,nO,guess_type,S,Hc,ERI,J,K,X,cp,F,Fp,e,c,P)
! ON(:) = 0d0
! do i=1,nO
! ON(i) = 1d0
! ON(i) = dble(2*i-1)
! end do
! call density_matrix(nBas,ON,c,P)
! Initialization
n_diis = 0
F_diis(:,:) = 0d0
error_diis(:,:) = 0d0
Conv = 1d0
nSCF = 0
!------------------------------------------------------------------------
! Main SCF loop
!------------------------------------------------------------------------
write(*,*)
write(*,*)'----------------------------------------------------'
write(*,*)'| RHF calculation |'
write(*,*)'----------------------------------------------------'
write(*,'(1X,A1,1X,A3,1X,A1,1X,A16,1X,A1,1X,A10,1X,A1,1X,A10,1X,A1,1X)') &
'|','#','|','HF energy','|','Conv','|','HL Gap','|'
write(*,*)'----------------------------------------------------'
do while(Conv > thresh .and. nSCF < maxSCF)
! Increment
nSCF = nSCF + 1
! Build Fock matrix
call Coulomb_matrix_AO_basis(nBas,P,ERI,J)
call exchange_matrix_AO_basis(nBas,P,ERI,K)
F(:,:) = Hc(:,:) + J(:,:) + 0.5d0*K(:,:)
! Check convergence
error = matmul(F,matmul(P,S)) - matmul(matmul(S,P),F)
Conv = maxval(abs(error))
! DIIS extrapolation
n_diis = min(n_diis+1,max_diis)
if(abs(rcond) > 1d-7) then
call DIIS_extrapolation(rcond,nBasSq,nBasSq,n_diis,error_diis,F_diis,error,F)
else
n_diis = 0
end if
! Diagonalize Fock matrix
Fp = matmul(transpose(X),matmul(F,X))
cp(:,:) = Fp(:,:)
call diagonalize_matrix(nBas,cp,e)
c = matmul(X,cp)
! Density matrix
P(:,:) = 2d0*matmul(c(:,1:nO),transpose(c(:,1:nO)))
! call density_matrix(nBas,ON,c,P)
! Compute HF energy
ERHF = trace_matrix(nBas,matmul(P,Hc)) &
+ 0.5d0*trace_matrix(nBas,matmul(P,J)) &
+ 0.25d0*trace_matrix(nBas,matmul(P,K))
! Compute HOMO-LUMO gap
if(nBas > nO) then
Gap = e(nO+1) - e(nO)
else
Gap = 0d0
endif
! Dump results
write(*,'(1X,A1,1X,I3,1X,A1,1X,F16.10,1X,A1,1X,F10.6,1X,A1,1X,F10.6,1X,A1,1X)') &
'|',nSCF,'|',ERHF+ENuc,'|',Conv,'|',Gap,'|'
enddo
write(*,*)'----------------------------------------------------'
!------------------------------------------------------------------------
! End of SCF loop
!------------------------------------------------------------------------
! Did it actually converge?
if(nSCF == maxSCF) then
write(*,*)
write(*,*)'!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!'
write(*,*)' Convergence failed '
write(*,*)'!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!'
write(*,*)
stop
endif
! Compute HF energy
ET = trace_matrix(nBas,matmul(P,T))
EV = trace_matrix(nBas,matmul(P,V))
EJ = 0.5d0*trace_matrix(nBas,matmul(P,J))
EK = 0.25d0*trace_matrix(nBas,matmul(P,K))
ERHF = ET + EV + EJ + EK
! Compute dipole moments
call dipole_moment(nBas,P,nNuc,ZNuc,rNuc,dipole_int,dipole)
call print_RHF(nBas,nO,e,C,ENuc,ET,EV,EJ,EK,ERHF,dipole)
! Compute Vx for post-HF calculations
call exchange_potential(nBas,c,K,Vx)
end subroutine RHF