2020-06-01 17:26:52 +02:00
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subroutine Bethe_Salpeter_AB_matrix_dynamic(eta,nBas,nC,nO,nV,nR,nS,lambda,eGW,OmRPA,OmBSE,rho,A_dyn,B_dyn)
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2020-06-01 11:35:17 +02:00
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! Compute the dynamic part of the Bethe-Salpeter equation matrices
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implicit none
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include 'parameters.h'
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! Input variables
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integer,intent(in) :: nBas,nC,nO,nV,nR,nS
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double precision,intent(in) :: eta
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double precision,intent(in) :: lambda
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double precision,intent(in) :: eGW(nBas)
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double precision,intent(in) :: OmRPA(nS)
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double precision,intent(in) :: OmBSE
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double precision,intent(in) :: rho(nBas,nBas,nS)
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! Local variables
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integer :: maxS
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2020-06-01 17:26:52 +02:00
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double precision :: chi_A,chi_B,eps,eps_A,eps_B
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2020-06-01 11:35:17 +02:00
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integer :: i,j,a,b,ia,jb,kc
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! Output variables
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2020-06-01 17:26:52 +02:00
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double precision,intent(out) :: A_dyn(nS,nS)
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double precision,intent(out) :: B_dyn(nS,nS)
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2020-06-01 11:35:17 +02:00
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! Initialization
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2020-06-01 17:26:52 +02:00
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A_dyn(:,:) = 0d0
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B_dyn(:,:) = 0d0
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2020-06-01 11:35:17 +02:00
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! Number of poles taken into account
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maxS = nS
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! Build dynamic A matrix
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ia = 0
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do i=nC+1,nO
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do a=nO+1,nBas-nR
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ia = ia + 1
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jb = 0
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do j=nC+1,nO
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do b=nO+1,nBas-nR
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jb = jb + 1
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chi_A = 0d0
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chi_B = 0d0
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do kc=1,maxS
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2020-06-06 21:34:39 +02:00
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chi_A = chi_A + rho(i,j,kc)*rho(a,b,kc)*OmRPA(kc)/(OmRPA(kc)**2 + eta**2)
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chi_B = chi_B + rho(i,b,kc)*rho(a,j,kc)*OmRPA(kc)/(OmRPA(kc)**2 + eta**2)
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2020-06-01 11:35:17 +02:00
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enddo
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2020-06-01 17:26:52 +02:00
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A_dyn(ia,jb) = A_dyn(ia,jb) - 4d0*lambda*chi_A
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B_dyn(ia,jb) = B_dyn(ia,jb) - 4d0*lambda*chi_B
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2020-06-01 11:35:17 +02:00
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2020-06-01 17:26:52 +02:00
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chi_A = 0d0
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chi_B = 0d0
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2020-06-01 11:35:17 +02:00
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do kc=1,maxS
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2020-06-04 22:40:14 +02:00
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eps_A = + OmBSE - OmRPA(kc) - (eGW(a) - eGW(j))
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chi_A = chi_A + rho(i,j,kc)*rho(a,b,kc)*eps_A/(eps_A**2 + eta**2)
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2020-06-01 11:35:17 +02:00
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2020-06-04 22:40:14 +02:00
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eps_A = + OmBSE - OmRPA(kc) - (eGW(b) - eGW(i))
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chi_A = chi_A + rho(i,j,kc)*rho(a,b,kc)*eps_A/(eps_A**2 + eta**2)
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2020-06-01 11:35:17 +02:00
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2020-06-04 22:40:14 +02:00
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eps_B = + OmBSE - OmRPA(kc) - (eGW(a) - eGW(b))
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chi_B = chi_B + rho(i,b,kc)*rho(a,j,kc)*eps_B/(eps_B**2 + eta**2)
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2020-06-01 11:35:17 +02:00
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2020-06-04 22:40:14 +02:00
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eps_B = + OmBSE - OmRPA(kc) - (eGW(j) - eGW(i))
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chi_B = chi_B + rho(i,b,kc)*rho(a,j,kc)*eps_B/(eps_B**2 + eta**2)
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2020-06-01 11:35:17 +02:00
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enddo
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2020-06-01 17:26:52 +02:00
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A_dyn(ia,jb) = A_dyn(ia,jb) - 2d0*lambda*chi_A
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2020-06-01 11:35:17 +02:00
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2020-06-01 17:26:52 +02:00
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B_dyn(ia,jb) = B_dyn(ia,jb) - 2d0*lambda*chi_B
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2020-06-01 11:35:17 +02:00
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enddo
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enddo
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enddo
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enddo
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end subroutine Bethe_Salpeter_AB_matrix_dynamic
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