#define _MM_ 1 #define _QM_ 2 #define _LA_ 3 module mod_link_atom use mod_memory, only: rp, ip, lp, mallocate, mfree use mod_topology, only: ommp_topology_type use mod_constants, only: angstrom2au, default_link_atom_dist, & default_link_atom_n_eel_remove use mod_nonbonded, only: vdw_geomgrad_inter use mod_bonded, only: ommp_bonded_type use mod_io, only: large_file_read use mod_utils, only: str_to_lower, str_uncomment implicit none private integer(ip), parameter :: link_atom_allocation_chunk = 20 type ommp_link_atom_type type(ommp_topology_type), pointer :: mmtop !! Topology of MM part of the system type(ommp_topology_type), pointer :: qmtop !! Topology of QM part of the system type(ommp_topology_type), allocatable :: qmmmtop !! Linked QM/MM topology integer(ip), allocatable :: mm2full(:), qm2full(:) !! Maps from qm and mm systems to full topology indexes integer(ip) :: nla !! Number of link atoms integer(ip), allocatable :: links(:,:) !! Indexes of link-involved atoms: !! links(_MM_,:) contains the index of MM atom in mmtop !! links(_QM_,:) contains the index of QM atom in qmtop !! links(_LA_,:) contains the index of link atom in qmtop real(rp), allocatable :: la_distance(:) !! Distance of link atom from QM atom integer(ip), allocatable :: vdw_screening_pairs(:,:) !! Pairs of vdw interactions that should be screened real(rp), allocatable :: vdw_screening_f(:) !! Screening factors for each vdw pair integer(ip) :: vdw_n_screening !! Number of screening vdw to be used type(ommp_bonded_type), allocatable :: bds end type public :: ommp_link_atom_type, init_link_atom, add_link_atom public :: link_atom_position, init_vdw_for_link_atom, init_bonded_for_link_atom public :: init_eel_for_link_atom public :: default_link_atom_dist, default_link_atom_n_eel_remove, link_atom_update_merged_topology public :: link_atom_bond_geomgrad, link_atom_angle_geomgrad, link_atom_torsion_geomgrad, & link_atom_project_grd contains subroutine init_link_atom(la, qmtop, mmtop) use mod_topology, only: merge_top use mod_constants, only: OMMP_VERBOSE_LOW use mod_io, only: ommp_message implicit none type(ommp_link_atom_type), intent(inout) :: la type(ommp_topology_type), intent(in), target :: qmtop, mmtop call mallocate('init_linkatoms [links]', & 3, link_atom_allocation_chunk, & la%links) call mallocate('init_linkatoms [la_distance]', & link_atom_allocation_chunk, la%la_distance) call mallocate('init_linkatoms [vdw_screening_f]', & link_atom_allocation_chunk, la%vdw_screening_f) call mallocate('init_linkatoms [vdw_screening_pairs]', 2, & link_atom_allocation_chunk, la%vdw_screening_pairs) la%nla = 0 la%vdw_n_screening = 0 la%qmtop => qmtop la%mmtop => mmtop call ommp_message("Creating merged topology", OMMP_VERBOSE_LOW, 'linkatom') allocate(la%qmmmtop) call merge_top(la%mmtop, la%qmtop, la%qmmmtop, la%mm2full, la%qm2full) allocate(la%bds) end subroutine subroutine link_atom_update_merged_topology(la) !! Update merged topology in linkatom object so that its coordinates !! are the same of mmtop and qmtop. implicit none type(ommp_link_atom_type), intent(inout) :: la integer(ip) :: i do i=1, la%mmtop%mm_atoms la%qmmmtop%cmm(:,la%mm2full(i)) = la%mmtop%cmm(:,i) end do do i=1, la%qmtop%mm_atoms la%qmmmtop%cmm(:,la%qm2full(i)) = la%qmtop%cmm(:,i) end do end subroutine subroutine add_link_atom(la, imm, iqm, ila, la_dist) use mod_constants, only: OMMP_STR_CHAR_MAX, OMMP_VERBOSE_LOW use mod_io, only: ommp_message use mod_topology, only: create_new_bond implicit none type(ommp_link_atom_type), intent(inout) :: la integer(ip), intent(in) :: imm integer(ip), intent(in) :: iqm integer(ip), intent(in) :: ila real(rp), intent(in) :: la_dist integer(ip), allocatable :: tmp(:,:) real(rp), allocatable :: rtmp(:) integer(ip) :: nmax character(len=OMMP_STR_CHAR_MAX) :: message nmax = size(la%links, 2) if(la%nla + 1 > nmax) then ! Reallocate links to accomodate new link atoms call mallocate('create_link_atom [tmp]', 3, nmax, tmp) call mallocate('create_link_atom [rtmp]', nmax, rtmp) tmp = la%links rtmp = la%la_distance call mfree('create_link_atom [la%links]', la%links) call mallocate('create_link_atom [la%links]', 3, nmax+link_atom_allocation_chunk, la%links) call mfree('create_link_atom [la%la_distance]', la%la_distance) call mallocate('create_link_atom [la%la_distance]', nmax+link_atom_allocation_chunk, la%la_distance) la%links = tmp(:,0:nmax) la%la_distance = rtmp(0:nmax) call mfree('create_link_atom [tmp]', tmp) call mfree('create_link_atom [rtmp]', rtmp) end if ! 0.2. Link atom creation and positioning la%nla = la%nla + 1 la%links(_MM_, la%nla) = imm la%links(_QM_, la%nla) = iqm la%links(_LA_, la%nla) = ila la%la_distance(la%nla) = la_dist if(la%qmmmtop%frozen(la%qm2full(iqm)) .and. la%qmmmtop%frozen(la%mm2full(imm))) then ! if QM atom and MM atoms are frozen, also LA is frozen la%qmmmtop%frozen(la%qm2full(ila)) = .true. end if call create_new_bond(la%qmmmtop, la%mm2full(imm), la%qm2full(iqm)) write(message, "(A, I0, A, I0, A, I0, A)") & "Created link atom MM [", imm, & "] - (LA) [", ila, "] - QM [", iqm, "]" call ommp_message(message, OMMP_VERBOSE_LOW, 'linkatom') end subroutine subroutine init_eel_for_link_atom(la, imm, ila, eel, prmfile) use mod_memory, only: mallocate, mfree use mod_prm, only: assign_mpoles use mod_electrostatics, only: ommp_electrostatics_type, & electrostatics_init, & remove_null_pol use mod_io, only: fatal_error, ommp_message use mod_constants, only: eps_rp, OMMP_VERBOSE_LOW, & OMMP_STR_CHAR_MAX, & OMMP_VERBOSE_DEBUG implicit none integer(ip), intent(in) :: imm integer(ip), intent(in) :: ila type(ommp_link_atom_type), intent(in) :: la type(ommp_electrostatics_type), intent(inout) :: eel character(len=*), intent(in) :: prmfile real(rp) :: removed_charge, qred, old_q, lastq integer(ip) :: n_eel_remove = default_link_atom_n_eel_remove integer(ip) :: ist, i, j, idx, ii type(ommp_electrostatics_type) :: tmp_eel character(len=OMMP_STR_CHAR_MAX) :: msg character(len=OMMP_STR_CHAR_MAX), allocatable :: prm_buf(:) integer(ip), allocatable :: attocheck(:) ! Check if in the complete topology some of the atoms connected ! to imm or imm itself do change their parameters. This is a ! problem that affects force-field in which parameters are ! assigned based on connectivity (AMOEBA). In particular we ! check only 1,2 and 1,3 neighbours of QM atom that are the ones ! that could be influenced by the new bond. Moreover we only ! take care of charges, as multipoles will be removed on those ! atoms in a while. call mallocate('init_eel_for_link_atom [attocheck]', & eel%top%conn(1)%ri(imm+1) - eel%top%conn(1)%ri(imm)+1, & attocheck) attocheck(1) = imm ii = 2 do i=eel%top%conn(1)%ri(imm), eel%top%conn(1)%ri(imm+1)-1 j = eel%top%conn(1)%ci(i) attocheck(ii) = j ii = ii + 1 end do write(msg, "(A, I0, A)") "Assigning electrostatic parameter to merged& & topology. Ignore all the warnings on & &link atom (", la%qm2full(ila), ")." call ommp_message(msg, OMMP_VERBOSE_LOW, 'linkatom') call electrostatics_init(tmp_eel, eel%amoeba, la%qmmmtop%mm_atoms, & la%qmmmtop) call large_file_read(prmfile, prm_buf) ! Remove comments from prm file !$omp parallel do do i=1, size(prm_buf) prm_buf(i) = str_to_lower(prm_buf(i)) prm_buf(i) = str_uncomment(prm_buf(i), '!') end do call assign_mpoles(tmp_eel, prm_buf) deallocate(prm_buf) do i=1, size(attocheck) j = attocheck(i) if(abs(tmp_eel%q(1,la%mm2full(j)) - eel%q(1,j)) > eps_rp) then write(msg, "(A, I0)") "Reassigning electrostatic parameter to& & atom ", j call ommp_message(msg, OMMP_VERBOSE_LOW, 'linkatom') write(msg, '(" Old parameters: q=", F6.2)') eel%q(1,j) call ommp_message(msg, OMMP_VERBOSE_DEBUG, 'linkatom') write(msg, '(" New parameters: q=", F6.2)') tmp_eel%q(1,la%mm2full(j)) call ommp_message(msg, OMMP_VERBOSE_DEBUG, 'linkatom') if(eel%amoeba) then eel%q0(:,j) = tmp_eel%q(:,la%mm2full(j)) else eel%q(:,j) = tmp_eel%q(:,la%mm2full(j)) end if end if end do call mfree('init_eel_for_link_atom [attocheck]', attocheck) ! Remove dipoles, multipoles, charges and polarizabilities ! on all the atoms that have a distance from (QM) atom less or equal to ! n_eel_remove. If n_eel_remove is 0, the MM electrostatic is not changed; ! if n_eel_remove is 1, only the connected atom is removed and so on. ! Removed charges is distributed to all the atoms 1 bond further away. if(n_eel_remove > 0) then if(n_eel_remove < 2) then call fatal_error("Electrostatic interaction should be removed at least on 1,2 and & &1,3 neighbour of linked QM atom") end if if(eel%amoeba) then old_q = sum(eel%q0(1,:)) else old_q = sum(eel%q(1,:)) end if removed_charge = 0.0 if(n_eel_remove > size(la%mmtop%conn)) then call fatal_error("Connectivity rebuild is not implemented in link atom") end if ! Remove charges, multipoles and polarizabilities if(eel%amoeba) then removed_charge = removed_charge + eel%q0(1,imm) lastq = eel%q0(1,imm) eel%q0(:,imm) = 0.0 if(eel%mm_polar(imm) > 0) & eel%pol(eel%mm_polar(imm)) = 0.0 else removed_charge = removed_charge + eel%q(1,imm) lastq = eel%q(1,imm) eel%q(:,imm) = 0.0 if(eel%mm_polar(imm) > 0) & eel%pol(eel%mm_polar(imm)) = 0.0 end if write(msg, '("Removed charge, multipoles and polarizabilities on atom ", I0, "[q=", F6.3, "]")') imm, lastq call ommp_message(msg, OMMP_VERBOSE_LOW, 'linkatom') do i=1, n_eel_remove-1 do j=eel%top%conn(i)%ri(imm), eel%top%conn(i)%ri(imm+1)-1 idx = eel%top%conn(i)%ci(j) if(eel%amoeba) then removed_charge = removed_charge + eel%q0(1,idx) lastq = eel%q0(1,idx) eel%q0(:,idx) = 0.0 if(eel%mm_polar(idx) > 0) & eel%pol(eel%mm_polar(idx)) = 0.0 else removed_charge = removed_charge + eel%q(1,idx) lastq = eel%q(1,idx) eel%q(:,idx) = 0.0 if(eel%mm_polar(idx) > 0) & eel%pol(eel%mm_polar(idx)) = 0.0 end if write(msg, '("Removed charge, multipoles and polarizabilities on atom ", I0, "[q=", F6.3, "]")') idx, lastq call ommp_message(msg, OMMP_VERBOSE_LOW, 'linkatom') end do end do ! Redistribute removed charge to preserve neutrality qred = removed_charge / (eel%top%conn(n_eel_remove)%ri(imm+1) - eel%top%conn(i)%ri(imm)) do j=eel%top%conn(n_eel_remove)%ri(imm), & eel%top%conn(n_eel_remove)%ri(imm+1)-1 idx = eel%top%conn(n_eel_remove)%ci(j) if(eel%amoeba) then eel%q0(1,idx) = eel%q0(1,idx) + qred else eel%q(1,idx) = eel%q(1,idx) + qred end if write(msg, '("Redistributing charge (", F6.3, " A.U.) on atom ", I0)') qred, idx call ommp_message(msg, OMMP_VERBOSE_LOW, 'linkatom') end do end if call remove_null_pol(eel) eel%M2M_done = .false. eel%M2Mgg_done = .false. eel%M2D_done = .false. eel%M2Dgg_done = .false. eel%ipd_done = .false. if(allocated(eel%TMat)) call mfree('update_coordinates [TMat]',eel%TMat) if(eel%amoeba) call rotate_multipoles(eel) write(msg, '("Charge of the systems passed from ", F6.3, " to ", F6.3, "A.U.")') & old_q, sum(eel%q(1,:)) call ommp_message(msg, OMMP_VERBOSE_LOW, 'linkatom') end subroutine subroutine link_atom_position(la, idx, crd) !! Compute the cartesian coordinates of link atom idx at !! the current geometry. implicit none type(ommp_link_atom_type), intent(in) :: la integer(ip), intent(in) :: idx real(rp), intent(out) :: crd(3) real(rp), dimension(3) :: rmm, rqm, dmmqm rmm = la%mmtop%cmm(:,la%links(_MM_,idx)) rqm = la%qmtop%cmm(:,la%links(_QM_,idx)) dmmqm = rmm-rqm dmmqm = dmmqm / norm2(dmmqm) crd = rqm + la%la_distance(idx) * dmmqm end subroutine subroutine check_vdw_pairs(la, n) !! Check if n new screening pairs could be allocated !! in la structure. If the allocated arrays are too !! small, they are reallocated on-the-fly. implicit none type(ommp_link_atom_type), intent(inout) :: la integer(ip), intent(in) :: n integer(ip), allocatable :: itmp(:,:) real(rp), allocatable :: rtmp(:) integer(ip) :: nnew, nold nnew = n + la%vdw_n_screening nold = size(la%vdw_screening_f) if(nnew > nold) then call mallocate('check_vdw_pairs [itmp]', 2, nold, itmp) call mallocate('check_vdw_pairs [rtmp]', nold, rtmp) itmp = la%vdw_screening_pairs rtmp = la%vdw_screening_f call mfree('check_vdw_pairs [vdw_screening_pairs]', la%vdw_screening_pairs) call mfree('check_vdw_pairs [vdw_screening_f]', la%vdw_screening_f) call mallocate('check_vdw_pairs [vdw_screening_pairs]', 2, nnew, la%vdw_screening_pairs) call mallocate('check_vdw_pairs [vdw_screening_f]', nnew, la%vdw_screening_f) la%vdw_screening_pairs(:,:nold) = itmp la%vdw_screening_f(:nold) = rtmp call mfree('check_vdw_pairs [itmp]', itmp) call mfree('check_vdw_pairs [rtmp]', rtmp) end if end subroutine subroutine add_screening_pair(la, iqm, imm, s) use mod_io, only: ommp_message use mod_constants, only: OMMP_STR_CHAR_MAX, OMMP_VERBOSE_DEBUG !! Insert a VdW screening pair in the link atom structure implicit none type(ommp_link_atom_type), intent(inout) :: la integer(ip), intent(in) :: iqm, imm real(rp), intent(in) :: s character(len=OMMP_STR_CHAR_MAX) :: message ! Just for safety, it should be done elsewhere for all the pairs ! ones want to insert in the structure. call check_vdw_pairs(la, 1) la%vdw_n_screening = la%vdw_n_screening + 1 la%vdw_screening_pairs(_QM_, la%vdw_n_screening) = iqm la%vdw_screening_pairs(_MM_, la%vdw_n_screening) = imm la%vdw_screening_f(la%vdw_n_screening) = s write(message, "(A, I0, A, I0, A, F3.2)") & "Screening VdW interactions between atoms ", imm, " (MM) & &and ", iqm, "(QM) by a factor ", 1.0 + s call ommp_message(message, OMMP_VERBOSE_DEBUG, 'linkatom') end subroutine subroutine init_vdw_for_link_atom(la, iqm, imm, vdw_screening) !! Initialize the quantities needed for vdw screening due to the !! presence of a link atom between iqm and imm use mod_topology, only: check_conn_matrix use mod_io, only: fatal_error, ommp_message use mod_constants, only: eps_rp, OMMP_STR_CHAR_MAX, OMMP_VERBOSE_DEBUG implicit none type(ommp_link_atom_type), intent(inout) :: la integer(ip), intent(in) :: iqm, imm real(rp), intent(in) :: vdw_screening(:) integer(ip) :: i, j, ineigh_qm, ineigh_mm, idist, iscr, & qmneigh(4), mmneigh(4) real(rp) :: screen character(len=OMMP_STR_CHAR_MAX) :: message ! Check that the connectivity matrices have been built up to the ! required order. call check_conn_matrix(la%qmtop, size(vdw_screening)-1) call check_conn_matrix(la%mmtop, size(vdw_screening)-1) ! Count how many interactions should be screened qmneigh(1) = 1 mmneigh(1) = 1 do i=2, size(vdw_screening) qmneigh(i) = la%qmtop%conn(i-1)%ri(iqm+1) - & la%qmtop%conn(i-1)%ri(iqm) mmneigh(i) = la%mmtop%conn(i-1)%ri(imm+1) - & la%mmtop%conn(i-1)%ri(imm) end do iscr = 0 do idist=1, size(vdw_screening) if(abs(vdw_screening(idist) - 1.0) > eps_rp) then do i=1, idist iscr = iscr + qmneigh(i) * mmneigh(idist-i+1) end do end if end do write(message, "(I0, A)") & iscr, " VdW interactions will be screened due to link atom" call ommp_message(message, OMMP_VERBOSE_DEBUG, 'linkatom') ! Check the allocation of vectors inside link atom structure call check_vdw_pairs(la, iscr) ! Insert the new screened interactions inside link atom structure do idist=1, size(vdw_screening) screen = vdw_screening(idist) - 1.0 if(abs(screen) > eps_rp) then do ineigh_qm=1, idist ineigh_mm = idist - ineigh_qm + 1 if(ineigh_qm == 1) then if(ineigh_mm == 1) then call add_screening_pair(la, iqm, imm, screen) else do i=la%mmtop%conn(ineigh_mm-1)%ri(imm), & la%mmtop%conn(ineigh_mm-1)%ri(imm+1) - 1 call add_screening_pair(la, & iqm, & la%mmtop%conn(ineigh_mm-1)%ci(i), & screen) end do end if else if(ineigh_mm == 1) then do i=la%qmtop%conn(ineigh_qm-1)%ri(iqm), & la%qmtop%conn(ineigh_qm-1)%ri(iqm+1) -1 call add_screening_pair(la, & la%qmtop%conn(ineigh_qm-1)%ci(i), & imm, & screen) end do else do i=la%mmtop%conn(ineigh_mm-1)%ri(imm), & la%mmtop%conn(ineigh_mm-1)%ri(imm+1) - 1 do j=la%qmtop%conn(ineigh_qm-1)%ri(iqm), & la%qmtop%conn(ineigh_qm-1)%ri(iqm+1) -1 call add_screening_pair(la, & la%qmtop%conn(ineigh_qm-1)%ci(j), & la%mmtop%conn(ineigh_mm-1)%ci(i), & screen) end do end do end if end if end do end if end do end subroutine subroutine init_bonded_for_link_atom(la, prmfile) !! Insert in the bonded parameter required for the link atom between iqm and imm use mod_prm, only: assign_bond, assign_angle, assign_torsion use mod_bonded, only: bonded_terminate, & bond_init, angle_init, torsion_init, & bond_terminate, angle_terminate, torsion_terminate use mod_bonded, only: OMMP_ANG_SIMPLE, OMMP_ANG_H0, OMMP_ANG_H1, & OMMP_ANG_H2, OMMP_ANG_INPLANE, & OMMP_ANG_INPLANE_H0, OMMP_ANG_INPLANE_H1 use mod_io, only: ommp_message, fatal_error use mod_constants, only: OMMP_STR_CHAR_MAX, OMMP_VERBOSE_LOW use mod_topology, only: check_conn_matrix implicit none type(ommp_link_atom_type), intent(inout), target :: la character(len=*), intent(in) :: prmfile type(ommp_bonded_type) :: tmp_bnd integer(ip), parameter :: maxt = 1024 integer(ip) :: ist, i, j, nqm, nterms, iterms(maxt) character(len=OMMP_STR_CHAR_MAX) :: message character(len=OMMP_STR_CHAR_MAX), allocatable :: prm_buf(:) call check_conn_matrix(la%qmmmtop, 4) tmp_bnd%top => la%qmmmtop la%bds%top => la%qmmmtop call large_file_read(prmfile, prm_buf) ! Remove comments from prm file !$omp parallel do do i=1, size(prm_buf) prm_buf(i) = str_to_lower(prm_buf(i)) prm_buf(i) = str_uncomment(prm_buf(i), '!') end do ! Bonded terms call assign_bond(tmp_bnd, prm_buf, la%qm2full, 2) if(tmp_bnd%use_bond) then nterms = 0 do i=1, tmp_bnd%nbond nqm = 0 if(any(la%qm2full == tmp_bnd%bondat(1,i))) nqm = nqm+1 if(any(la%qm2full == tmp_bnd%bondat(2,i))) nqm = nqm+1 if(nqm == 1) then nterms = nterms + 1 if(nterms > maxt) then call fatal_error("Maximum number of terms to be added due to link atom & &exceeded. This is probably a bug.") end if iterms(nterms) = i end if end do if(la%bds%use_bond) then ! Bond terms are already initializad by a previous ! link atom call bond_terminate(la%bds) end if call bond_init(la%bds, nterms) do i=1, nterms la%bds%bondat(:,i) = tmp_bnd%bondat(:,iterms(i)) la%bds%kbond(i) = tmp_bnd%kbond(iterms(i)) la%bds%l0bond(i) = tmp_bnd%l0bond(iterms(i)) end do la%bds%bond_cubic = tmp_bnd%bond_cubic la%bds%bond_quartic = tmp_bnd%bond_quartic write(message, "(I0, A)") nterms, " bond terms added due to link atoms." call ommp_message(message, OMMP_VERBOSE_LOW, "linkatom") end if call assign_angle(tmp_bnd, prm_buf, la%qm2full, 2) if(tmp_bnd%use_angle) then nterms = 0 do i=1, tmp_bnd%nangle if(tmp_bnd%anglety(i) == OMMP_ANG_SIMPLE .or. & tmp_bnd%anglety(i) == OMMP_ANG_H0 .or. & tmp_bnd%anglety(i) == OMMP_ANG_H1 .or. & tmp_bnd%anglety(i) == OMMP_ANG_H2) then nqm = 0 if(any(la%qm2full == tmp_bnd%angleat(1,i))) nqm = nqm+1 if(any(la%qm2full == tmp_bnd%angleat(2,i))) nqm = nqm+1 if(any(la%qm2full == tmp_bnd%angleat(3,i))) nqm = nqm+1 if(nqm == 1) then nterms = nterms + 1 if(nterms > maxt) then call fatal_error("Maximum number of terms to be added due to link atom & &exceeded. This is probably a bug.") end if iterms(nterms) = i end if else if(tmp_bnd%anglety(i) == OMMP_ANG_INPLANE .or. & tmp_bnd%anglety(i) == OMMP_ANG_INPLANE_H0 .or. & tmp_bnd%anglety(i) == OMMP_ANG_INPLANE_H1) then nqm = 0 if(any(la%qm2full == tmp_bnd%angleat(1,i))) nqm = nqm+1 if(any(la%qm2full == tmp_bnd%angleat(2,i))) nqm = nqm+1 if(any(la%qm2full == tmp_bnd%angleat(3,i))) nqm = nqm+1 if(nqm == 1 .and. .not. any(la%qm2full == tmp_bnd%angauxat(i))) then nterms = nterms + 1 if(nterms > maxt) then call fatal_error("Maximum number of terms to be added due to link atom & &exceeded. This is probably a bug.") end if iterms(nterms) = i end if end if end do if(la%bds%use_angle) then call angle_terminate(la%bds) end if call angle_init(la%bds, nterms) do i=1, nterms la%bds%angleat(:,i) = tmp_bnd%angleat(:,iterms(i)) la%bds%anglety(i) = tmp_bnd%anglety(iterms(i)) la%bds%angauxat(i) = tmp_bnd%angauxat(iterms(i)) la%bds%kangle(i) = tmp_bnd%kangle(iterms(i)) la%bds%eqangle(i) = tmp_bnd%eqangle(iterms(i)) end do la%bds%angle_cubic = tmp_bnd%angle_cubic la%bds%angle_quartic = tmp_bnd%angle_quartic la%bds%angle_pentic = tmp_bnd%angle_pentic la%bds%angle_sextic = tmp_bnd%angle_sextic write(message, "(I0, A)") nterms, " angle terms added due to link atoms." call ommp_message(message, OMMP_VERBOSE_LOW, "linkatom") end if call assign_torsion(tmp_bnd, prm_buf) if(tmp_bnd%use_torsion) then nterms = 0 do i=1, tmp_bnd%ntorsion nqm = 0 if(any(la%qm2full == tmp_bnd%torsionat(1,i))) nqm = nqm+1 if(any(la%qm2full == tmp_bnd%torsionat(2,i))) nqm = nqm+1 if(any(la%qm2full == tmp_bnd%torsionat(3,i))) nqm = nqm+1 if(any(la%qm2full == tmp_bnd%torsionat(4,i))) nqm = nqm+1 !! Link atoms should never appear in bonded interactions! do j=1, 4 if(any(la%qm2full(la%links(_LA_,1:la%nla)) == tmp_bnd%torsionat(j,i))) nqm = -1 end do if(nqm == 1 .or. nqm == 2) then nterms = nterms + 1 if(nterms > maxt) then call fatal_error("Maximum number of terms to be added due to link atom & &exceeded. This is probably a bug.") end if iterms(nterms) = i end if end do if(la%bds%use_torsion) then call torsion_terminate(la%bds) end if call torsion_init(la%bds, nterms) do i=1, nterms la%bds%torsionat(:,i) = tmp_bnd%torsionat(:,iterms(i)) la%bds%torsn(:,i) = tmp_bnd%torsn(:,iterms(i)) la%bds%torsamp(:,i) = tmp_bnd%torsamp(:,iterms(i)) la%bds%torsphase(:,i) = tmp_bnd%torsphase(:,iterms(i)) end do write(message, "(I0, A)") nterms, " torsion terms added due to link atoms." call ommp_message(message, OMMP_VERBOSE_LOW, "linkatom") end if deallocate(prm_buf) call bonded_terminate(tmp_bnd) end subroutine subroutine link_atom_bond_geomgrad(la, qmg, mmg, doqm, domm) use mod_bonded, only: bond_geomgrad implicit none type(ommp_link_atom_type), intent(in) :: la real(rp), intent(inout) :: qmg(:,:), & mmg(:,:) logical, intent(in) :: doqm, domm real(rp), allocatable :: grd(:,:) integer(ip) :: i call mallocate('link_atom_bond_geomgrad [grd]', & 3, la%qmmmtop%mm_atoms, grd) grd = 0.0 call bond_geomgrad(la%bds, grd) if(doqm) then do i=1, la%qmtop%mm_atoms qmg(:,i) = qmg(:,i) + grd(:,la%qm2full(i)) end do end if if(domm) then do i=1, la%mmtop%mm_atoms mmg(:,i) = mmg(:,i) + grd(:,la%mm2full(i)) end do end if call mfree('link_atom_bond_geomgrad [grd]', grd) end subroutine subroutine link_atom_angle_geomgrad(la, qmg, mmg, doqm, domm) use mod_bonded, only: angle_geomgrad implicit none type(ommp_link_atom_type), intent(in) :: la real(rp), intent(inout) :: qmg(:,:), & mmg(:,:) logical, intent(in) :: doqm, domm real(rp), allocatable :: grd(:,:) integer(ip) :: i call mallocate('link_atom_bond_geomgrad [grd]', & 3, la%qmmmtop%mm_atoms, grd) grd = 0.0 call angle_geomgrad(la%bds, grd) if(doqm) then do i=1, la%qmtop%mm_atoms qmg(:,i) = qmg(:,i) + grd(:,la%qm2full(i)) end do end if if(domm) then do i=1, la%mmtop%mm_atoms mmg(:,i) = mmg(:,i) + grd(:,la%mm2full(i)) end do end if call mfree('link_atom_bond_geomgrad [grd]', grd) end subroutine subroutine link_atom_torsion_geomgrad(la, qmg, mmg, doqm, domm) use mod_bonded, only: torsion_geomgrad implicit none type(ommp_link_atom_type), intent(in) :: la real(rp), intent(inout) :: qmg(:,:), & mmg(:,:) logical, intent(in) :: doqm, domm real(rp), allocatable :: grd(:,:) integer(ip) :: i call mallocate('link_atom_bond_geomgrad [grd]', & 3, la%qmmmtop%mm_atoms, grd) grd = 0.0 call torsion_geomgrad(la%bds, grd) if(doqm) then do i=1, la%qmtop%mm_atoms qmg(:,i) = qmg(:,i) + grd(:,la%qm2full(i)) end do end if if(domm) then do i=1, la%mmtop%mm_atoms mmg(:,i) = mmg(:,i) + grd(:,la%mm2full(i)) end do end if call mfree('link_atom_bond_geomgrad [grd]', grd) end subroutine subroutine link_atom_project_grd(la, laforces, qmg, mmg) use mod_utils, only: versor_der implicit none type(ommp_link_atom_type), intent(in) :: la real(rp), intent(in) :: laforces(3, la%nla) real(rp), intent(inout) :: qmg(3,la%qmtop%mm_atoms), & mmg(3,la%mmtop%mm_atoms) integer(ip) :: i, iqm, imm, ila real(rp) :: delta(3), rmm(3), rqm(3), dedqm(3,3), dedmm(3,3) do i=1, la%nla iqm = la%links(_QM_,i) imm = la%links(_MM_,i) ila = la%links(_LA_,i) rmm = la%mmtop%cmm(:,imm) rqm = la%qmtop%cmm(:,iqm) delta = rmm-rqm dedmm = la%la_distance(i) * versor_der(delta) dedqm = 0.0 dedqm(1,1) = 1.0 dedqm(2,2) = 1.0 dedqm(3,3) = 1.0 dedqm = dedqm - dedmm if(.not. la%qmmmtop%frozen(la%qm2full(iqm))) & qmg(:, iqm) = qmg(:, iqm) + matmul(dedqm, laforces(:,i)) if(.not. la%qmmmtop%frozen(la%mm2full(imm))) & mmg(:, imm) = mmg(:, imm) + matmul(dedmm, laforces(:,i)) qmg(:, ila) = -laforces(:,i) end do end subroutine end module