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qp2/src/dft_utils_one_e/shifted_potential.irp.f
2019-01-25 11:39:31 +01:00

17 lines
618 B
Fortran

BEGIN_PROVIDER [double precision, shifting_constant, (N_states)]
implicit none
BEGIN_DOC
! shifting_constant = (E_{Hxc} - <\Psi | V_{Hxc} | \Psi>) / N_elec
! constant to add to the potential in order to obtain the variational energy as
! the eigenvalue of the effective long-range Hamiltonian
! (see original paper of Levy PRL 113, 113002 (2014), equation (17) )
END_DOC
integer :: istate
do istate = 1, N_states
shifting_constant(istate) = energy_x(istate) + energy_c(istate) + short_range_Hartree(istate) - Trace_v_Hxc(istate)
enddo
shifting_constant = shifting_constant / dble(elec_num)
END_PROVIDER