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2.0 KiB
2.0 KiB
State average energy
Calculation of the state average energy from the integrals and the density matrices.
\begin{align*} E = \sum_{ij} h_{ij} \gamma_{ij} + \frac{1}{2} v_{ij}^{kl} \Gamma_{ij}^{kl} \end{align*}$h_{ij}$: mono-electronic integral $\gamma_{ij}$: one electron density matrix $v_{ij}^{kl}$: bi-electronic integral $\Gamma_{ij}^{kl}$: two electrons density matrix
TODO: OMP version
PROVIDED:
mo_one_e_integrals | double precision | mono-electronic integrals |
get_two_e_integral | double precision | bi-electronic integrals |
one_e_dm_mo | double precision | one electron density matrix |
two_e_dm_mo | double precision | two electrons density matrix |
nuclear_repulsion | double precision | nuclear repulsion |
mo_num | integer | number of MOs |
Output:
energy | double precision | state average energy |
Internal:
mono_e | double precision | mono-electronic energy |
bi_e | double precision | bi-electronic energy |
i,j,k,l | integer | indexes to loop over the MOs |
subroutine state_average_energy(energy)
implicit none
double precision, intent(out) :: energy
double precision :: get_two_e_integral
double precision :: mono_e, bi_e
integer :: i,j,k,l
! mono electronic part
mono_e = 0d0
do j = 1, mo_num
do i = 1, mo_num
mono_e = mono_e + mo_one_e_integrals(i,j) * one_e_dm_mo(i,j)
enddo
enddo
! bi electronic part
bi_e = 0d0
do l = 1, mo_num
do k = 1, mo_num
do j = 1, mo_num
do i = 1, mo_num
bi_e = bi_e + get_two_e_integral(i,j,k,l,mo_integrals_map) * two_e_dm_mo(i,j,k,l)
enddo
enddo
enddo
enddo
! State average energy
energy = mono_e + 0.5d0 * bi_e + nuclear_repulsion
! Check
!call print_energy_components
print*,'State average energy:', energy
!print*,ci_energy
end