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quantum-espresso/PP/do_shift_ew.f90

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07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
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!
! Copyright (C) 2001 PWSCF group
! This file is distributed under the terms of the
! GNU General Public License. See the file `License'
! in the root directory of the present distribution,
! or http://www.gnu.org/copyleft/gpl.txt .
!
General cleanup of intrinsic functions: conversion to real => DBLE (including real part of a complex number) conversion to complex => CMPLX complex conjugate => CONJG imaginary part => AIMAG All functions are uppercase. CMPLX is preprocessed by f_defs.h and performs an explicit cast: #define CMPLX(a,b) cmplx(a,b,kind=DP) This implies that 1) f_defs.h must be included whenever a CMPLX is present, 2) CMPLX should stay in a single line, 3) DP must be defined. All occurrences of real, float, dreal, dfloat, dconjg, dimag, dcmplx removed - please do not reintroduce any of them. Tested only with ifc7 and g95 - beware unintended side effects Maybe not the best solution (explicit casts everywhere would be better) but it can be easily changed with a script if the need arises. The following code might be used to test for possible trouble: program test_intrinsic implicit none integer, parameter :: dp = selected_real_kind(14,200) real (kind=dp) :: a = 0.123456789012345_dp real (kind=dp) :: b = 0.987654321098765_dp complex (kind=dp) :: c = ( 0.123456789012345_dp, 0.987654321098765_dp) print *, ' A = ', a print *, ' DBLE(A)= ', DBLE(a) print *, ' C = ', c print *, 'CONJG(C)= ', CONJG(c) print *, 'DBLE(c),AIMAG(C) = ', DBLE(c), AIMAG(c) print *, 'CMPLX(A,B,kind=dp)= ', CMPLX( a, b, kind=dp) end program test_intrinsic Note that CMPLX and REAL without a cast yield single precision numbers on ifc7 and g95 !!! git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2133 c92efa57-630b-4861-b058-cf58834340f0
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#include "f_defs.h"
07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
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!
!-----------------------------------------------------------------------
subroutine do_shift_ew (alat, nat, ntyp, ityp, zv, delta_zv, at, bg, tau, &
omega, g, gg, ngm, gcutm, gstart, gamma_only, shift_ion)
!-----------------------------------------------------------------------
!
! Calculates Ewald energy with both G- and R-space terms.
! Determines optimal alpha. Should hopefully work for any structure.
!
!
USE kinds
implicit none
!
! first the dummy variables
!
integer :: nat, ntyp, ityp (nat), ngm, gstart
! input: number of atoms in the unit cell
! input: number of different types of atoms
! input: the type of each atom
! input: number of plane waves for G sum
! input: first non-zero G vector
logical :: gamma_only
dbl => DP (defined as previously dbl was) syntax for declarations: real(DP), without "kind=" git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2135 c92efa57-630b-4861-b058-cf58834340f0
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real(DP) :: tau (3, nat), g (3, ngm), gg (ngm), zv (ntyp), &
07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
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at (3, 3), bg (3, 3), omega, alat, gcutm, delta_zv(ntyp), &
shift_ion(nat)
! input: the positions of the atoms in the cell
! input: the coordinates of G vectors
! input: the square moduli of G vectors
! input: the charge of each type of atoms
! input: the direct lattice vectors
! input: the reciprocal lattice vectors
! input: the volume of the unit cell
! input: lattice parameter
! input: cut-off of g vectors
dbl => DP (defined as previously dbl was) syntax for declarations: real(DP), without "kind=" git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2135 c92efa57-630b-4861-b058-cf58834340f0
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real(DP) :: ewald
07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
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! output: the ewald energy
!
! here the local variables
!
integer, parameter :: mxr = 50
! the maximum number of R vectors included in r
dbl => DP (defined as previously dbl was) syntax for declarations: real(DP), without "kind=" git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2135 c92efa57-630b-4861-b058-cf58834340f0
2005-08-28 22:09:42 +08:00
real(DP), parameter :: tpi = 2.d0 * 3.141592653589793d0
real(DP), parameter :: e2 = 2.d0
07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
2004-10-07 21:31:54 +08:00
! the square of the electron charge (Ry atomic units)
integer :: ng, nr, na, nb, nt, nrm, ipol
! counter over reciprocal G vectors
! counter over direct vectors
! counter on atoms
! counter on atoms
! counter on atomic types
! number of R vectors included in r sum
! counter on polarization
dbl => DP (defined as previously dbl was) syntax for declarations: real(DP), without "kind=" git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2135 c92efa57-630b-4861-b058-cf58834340f0
2005-08-28 22:09:42 +08:00
real(DP) :: charge, tpiba2, ewaldg, ewaldr, dtau (3), alpha, &
07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
2004-10-07 21:31:54 +08:00
r (3, mxr), r2 (mxr), rmax, rr, upperbound, fact, arg
! total ionic charge in the cell
! length in reciprocal space
! ewald energy computed in reciprocal space
! ewald energy computed in real space
! the difference tau_s - tau_s'
! alpha term in ewald sum
! input of the rgen routine ( not used here )
! the square modulus of R_j-tau_s-tau_s'
! the maximum radius to consider real space sum
! buffer variable
! used to optimize alpha
dbl => DP (defined as previously dbl was) syntax for declarations: real(DP), without "kind=" git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2135 c92efa57-630b-4861-b058-cf58834340f0
2005-08-28 22:09:42 +08:00
complex(DP), allocatable :: rhon(:)
real(DP), external :: erfc
07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
2004-10-07 21:31:54 +08:00
allocate (rhon(ngm))
shift_ion(:) = 0.d0
tpiba2 = (tpi / alat) **2
charge = 0.d0
do na = 1, nat
charge = charge+zv (ityp (na) )
enddo
alpha = 2.9d0
100 alpha = alpha - 0.1d0
!
! choose alpha in order to have convergence in the sum over G
! upperbound is a safe upper bound for the error in the sum over G
!
if (alpha.le.0.d0) call errore ('ewald', 'optimal alpha not found', 1)
upperbound = 2.d0 * charge**2 * sqrt (2.d0 * alpha / tpi) * erfc ( &
sqrt (tpiba2 * gcutm / 4.d0 / alpha) )
if (upperbound.gt.1.0d-7) goto 100
!
! G-space sum here.
! Determine if this processor contains G=0 and set the constant term
!
if (gstart==2) then
do na =1,nat
shift_ion(na) = - charge * delta_zv(ityp(na)) /alpha/ 4.0
end do
endif
if (gamma_only) then
fact = 2.d0
else
fact = 1.d0
end if
do ng = gstart, ngm
rhon(ng) = (0.d0, 0.d0)
do na =1, nat
arg = (g (1, ng) * tau (1, na) + &
g (2, ng) * tau (2, na) + &
g (3, ng) * tau (3, na) ) * tpi
General cleanup of intrinsic functions: conversion to real => DBLE (including real part of a complex number) conversion to complex => CMPLX complex conjugate => CONJG imaginary part => AIMAG All functions are uppercase. CMPLX is preprocessed by f_defs.h and performs an explicit cast: #define CMPLX(a,b) cmplx(a,b,kind=DP) This implies that 1) f_defs.h must be included whenever a CMPLX is present, 2) CMPLX should stay in a single line, 3) DP must be defined. All occurrences of real, float, dreal, dfloat, dconjg, dimag, dcmplx removed - please do not reintroduce any of them. Tested only with ifc7 and g95 - beware unintended side effects Maybe not the best solution (explicit casts everywhere would be better) but it can be easily changed with a script if the need arises. The following code might be used to test for possible trouble: program test_intrinsic implicit none integer, parameter :: dp = selected_real_kind(14,200) real (kind=dp) :: a = 0.123456789012345_dp real (kind=dp) :: b = 0.987654321098765_dp complex (kind=dp) :: c = ( 0.123456789012345_dp, 0.987654321098765_dp) print *, ' A = ', a print *, ' DBLE(A)= ', DBLE(a) print *, ' C = ', c print *, 'CONJG(C)= ', CONJG(c) print *, 'DBLE(c),AIMAG(C) = ', DBLE(c), AIMAG(c) print *, 'CMPLX(A,B,kind=dp)= ', CMPLX( a, b, kind=dp) end program test_intrinsic Note that CMPLX and REAL without a cast yield single precision numbers on ifc7 and g95 !!! git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2133 c92efa57-630b-4861-b058-cf58834340f0
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rhon(ng) = rhon(ng) + zv (ityp(na)) * CMPLX (cos (arg), -sin (arg))
07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
2004-10-07 21:31:54 +08:00
enddo
end do
do na=1,nat
do ng=gstart, ngm
arg = (g (1, ng) * tau (1, na) + g (2, ng) * tau (2, na) &
+ g (3, ng) * tau (3, na) ) * tpi
shift_ion(na) = shift_ion(na) + fact * delta_zv(ityp(na)) * &
General cleanup of intrinsic functions: conversion to real => DBLE (including real part of a complex number) conversion to complex => CMPLX complex conjugate => CONJG imaginary part => AIMAG All functions are uppercase. CMPLX is preprocessed by f_defs.h and performs an explicit cast: #define CMPLX(a,b) cmplx(a,b,kind=DP) This implies that 1) f_defs.h must be included whenever a CMPLX is present, 2) CMPLX should stay in a single line, 3) DP must be defined. All occurrences of real, float, dreal, dfloat, dconjg, dimag, dcmplx removed - please do not reintroduce any of them. Tested only with ifc7 and g95 - beware unintended side effects Maybe not the best solution (explicit casts everywhere would be better) but it can be easily changed with a script if the need arises. The following code might be used to test for possible trouble: program test_intrinsic implicit none integer, parameter :: dp = selected_real_kind(14,200) real (kind=dp) :: a = 0.123456789012345_dp real (kind=dp) :: b = 0.987654321098765_dp complex (kind=dp) :: c = ( 0.123456789012345_dp, 0.987654321098765_dp) print *, ' A = ', a print *, ' DBLE(A)= ', DBLE(a) print *, ' C = ', c print *, 'CONJG(C)= ', CONJG(c) print *, 'DBLE(c),AIMAG(C) = ', DBLE(c), AIMAG(c) print *, 'CMPLX(A,B,kind=dp)= ', CMPLX( a, b, kind=dp) end program test_intrinsic Note that CMPLX and REAL without a cast yield single precision numbers on ifc7 and g95 !!! git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2133 c92efa57-630b-4861-b058-cf58834340f0
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CONJG(rhon(ng)) * CMPLX (cos (arg), -sin (arg)) * &
07 Oct 2004 - a new utility virtual.x has been added to upftools that can combine two pseudopotentials in UPF format to produce a third one (in the same format) for the virtual atom Vvirt = x * V1 + (1-x) V2 . For the time being it has only limited functionality as the two pseudos need to be defined on the same radial grid. (SdG) - a new utility initial_state.x has been added to PP that can computed the core level shift in the initial state approximation... in practice the first order derivative of the total energy with respect to DeltaV=V(excited)-V(GS). It is the analogue (via Janak theorem) of the core eigenvalue in the pseudopotential framework where the core electrons do not exist. In the present status it require both V(excited) and V(GS) to be defined in the preceeding SCF calculation. (SdG) git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1369 c92efa57-630b-4861-b058-cf58834340f0
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exp ( -gg(ng)*tpiba2/alpha/4.d0) / gg(ng)/tpiba2
enddo
enddo
shift_ion(:) = 2.d0 * tpi / omega * shift_ion(:)
!
! Here add the other constant term
!
if (gstart.eq.2) then
do na = 1, nat
shift_ion(na) = shift_ion(na) - &
zv (ityp (na) ) * delta_zv(ityp(na)) * &
sqrt (8.d0/tpi*alpha)
enddo
endif
!
! R-space sum here (only for the processor that contains G=0)
!
if (gstart.eq.2) then
rmax = 4.d0 / sqrt (alpha) / alat
!
! with this choice terms up to ZiZj*erfc(4) are counted (erfc(4)=2x10^-8
!
do na = 1, nat
do nb = 1, nat
do ipol = 1, 3
dtau (ipol) = tau (ipol, na) - tau (ipol, nb)
enddo
!
! generates nearest-neighbors shells
!
call rgen (dtau, rmax, mxr, at, bg, r, r2, nrm)
!
! and sum to the real space part
!
do nr = 1, nrm
rr = sqrt (r2 (nr) ) * alat
shift_ion(na) = shift_ion(na) + &
delta_zv(ityp(na)) * zv (ityp (nb) ) * &
erfc ( sqrt (alpha) * rr) / rr
enddo
enddo
enddo
endif
shift_ion(:) = e2 * shift_ion(:)
#ifdef __PARA
call reduce (nat, shift_ion)
#endif
deallocate (rhon)
return
end subroutine do_shift_ew