! This file is part of s-dftd3. ! SPDX-Identifier: LGPL-3.0-or-later ! ! s-dftd3 is free software: you can redistribute it and/or modify it under ! the terms of the GNU Lesser General Public License as published by ! the Free Software Foundation, either version 3 of the License, or ! (at your option) any later version. ! ! s-dftd3 is distributed in the hope that it will be useful, ! but WITHOUT ANY WARRANTY; without even the implied warranty of ! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ! GNU Lesser General Public License for more details. ! ! You should have received a copy of the GNU Lesser General Public License ! along with s-dftd3. If not, see <https://www.gnu.org/licenses/>. module dftd3_damping_optimizedpower use dftd3_damping, only : damping_param use dftd3_damping_atm, only : get_atm_dispersion, get_atm_pairwise_dispersion use dftd3_param, only : d3_param use mctc_env, only : wp use mctc_io, only : structure_type implicit none public :: optimizedpower_damping_param, new_optimizedpower_damping !> Optimized power damping model type, extends(damping_param) :: optimizedpower_damping_param real(wp) :: s6 real(wp) :: s8 real(wp) :: s9 real(wp) :: a1 real(wp) :: a2 real(wp) :: alp real(wp) :: bet contains !> Evaluate pairwise dispersion energy expression procedure :: get_dispersion2 !> Evaluate ATM three-body dispersion energy expression procedure :: get_dispersion3 !> Evaluate pairwise representation of additive dispersion energy procedure :: get_pairwise_dispersion2 !> Evaluate pairwise representation of non-additive dispersion energy procedure :: get_pairwise_dispersion3 end type optimizedpower_damping_param real(wp), parameter :: rs9 = 4.0_wp/3.0_wp contains !> Create new optimized power damping model subroutine new_optimizedpower_damping(self, param) !> Optimized power damping parameters type(optimizedpower_damping_param), intent(out) :: self !> Parameters type(d3_param), intent(in) :: param self%s6 = param%s6 self%s8 = param%s8 self%s9 = param%s9 self%a1 = param%a1 self%a2 = param%a2 self%alp = param%alp self%bet = param%bet end subroutine new_optimizedpower_damping !> Evaluation of the dispersion energy expression subroutine get_dispersion2(self, mol, trans, cutoff, rvdw, r4r2, c6, dc6dcn, & & energy, dEdcn, gradient, sigma) !> Damping parameters class(optimizedpower_damping_param), intent(in) :: self !> Molecular structure data class(structure_type), intent(in) :: mol !> Lattice points real(wp), intent(in) :: trans(:, :) !> Real space cutoff real(wp), intent(in) :: cutoff !> Van-der-Waals radii for damping function real(wp), intent(in) :: rvdw(:, :) !> Expectation values for C8 extrapolation real(wp), intent(in) :: r4r2(:) !> C6 coefficients for all atom pairs. real(wp), intent(in) :: c6(:, :) !> Derivative of the C6 w.r.t. the coordination number real(wp), intent(in), optional :: dc6dcn(:, :) !> Dispersion energy real(wp), intent(inout) :: energy(:) !> Derivative of the energy w.r.t. the coordination number real(wp), intent(inout), optional :: dEdcn(:) !> Dispersion gradient real(wp), intent(inout), optional :: gradient(:, :) !> Dispersion virial real(wp), intent(inout), optional :: sigma(:, :) logical :: grad if (abs(self%s6) < epsilon(1.0_wp) .and. abs(self%s8) < epsilon(1.0_wp)) return grad = present(dc6dcn) .and. present(dEdcn) .and. present(gradient) & & .and. present(sigma) if (grad) then call get_dispersion_derivs(self, mol, trans, cutoff, rvdw, r4r2, c6, dc6dcn, & & energy, dEdcn, gradient, sigma) else call get_dispersion_energy(self, mol, trans, cutoff, rvdw, r4r2, c6, energy) end if end subroutine get_dispersion2 !> Evaluation of the dispersion energy expression subroutine get_dispersion_energy(self, mol, trans, cutoff, rvdw, r4r2, c6, energy) !> Damping parameters class(optimizedpower_damping_param), intent(in) :: self !> Molecular structure data class(structure_type), intent(in) :: mol !> Lattice points real(wp), intent(in) :: trans(:, :) !> Real space cutoff real(wp), intent(in) :: cutoff !> Van-der-Waals radii for damping function real(wp), intent(in) :: rvdw(:, :) !> Expectation values for C8 extrapolation real(wp), intent(in) :: r4r2(:) !> C6 coefficients for all atom pairs. real(wp), intent(in) :: c6(:, :) !> Dispersion energy real(wp), intent(inout) :: energy(:) integer :: iat, jat, izp, jzp, jtr real(wp) :: vec(3), r2, cutoff2, r0ij, rrij, c6ij, t6, t8, edisp, dE, rb, ab cutoff2 = cutoff*cutoff !$omp parallel do schedule(runtime) default(none) reduction(+:energy) & !$omp shared(mol, self, c6, trans, cutoff2, r4r2) private(iat, jat, izp, jzp, & !$omp& jtr, vec, r2, r0ij, rrij, c6ij, t6, t8, edisp, dE, rb, ab) do iat = 1, mol%nat izp = mol%id(iat) do jat = 1, iat jzp = mol%id(jat) rrij = 3*r4r2(izp)*r4r2(jzp) r0ij = self%a1 * sqrt(rrij) + self%a2 c6ij = c6(jat, iat) do jtr = 1, size(trans, 2) vec(:) = mol%xyz(:, iat) - (mol%xyz(:, jat) + trans(:, jtr)) r2 = vec(1)*vec(1) + vec(2)*vec(2) + vec(3)*vec(3) if (r2 > cutoff2 .or. r2 < epsilon(1.0_wp)) cycle rb = r2**(self%bet*0.5_wp) ab = r0ij**self%bet t6 = rb/(rb*r2**3 + ab*r0ij**6) t8 = rb/(rb*r2**4 + ab*r0ij**8) edisp = self%s6*t6 + self%s8*rrij*t8 dE = -c6ij*edisp * 0.5_wp energy(iat) = energy(iat) + dE if (iat /= jat) then energy(jat) = energy(jat) + dE end if end do end do end do end subroutine get_dispersion_energy !> Evaluation of the dispersion energy expression subroutine get_dispersion_derivs(self, mol, trans, cutoff, rvdw, r4r2, c6, dc6dcn, & & energy, dEdcn, gradient, sigma) !> Damping parameters class(optimizedpower_damping_param), intent(in) :: self !> Molecular structure data class(structure_type), intent(in) :: mol !> Lattice points real(wp), intent(in) :: trans(:, :) !> Real space cutoff real(wp), intent(in) :: cutoff !> Van-der-Waals radii for damping function real(wp), intent(in) :: rvdw(:, :) !> Expectation values for C8 extrapolation real(wp), intent(in) :: r4r2(:) !> C6 coefficients for all atom pairs. real(wp), intent(in) :: c6(:, :) !> Derivative of the C6 w.r.t. the coordination number real(wp), intent(in) :: dc6dcn(:, :) !> Dispersion energy real(wp), intent(inout) :: energy(:) !> Derivative of the energy w.r.t. the coordination number real(wp), intent(inout) :: dEdcn(:) !> Dispersion gradient real(wp), intent(inout) :: gradient(:, :) !> Dispersion virial real(wp), intent(inout) :: sigma(:, :) integer :: iat, jat, izp, jzp, jtr real(wp) :: vec(3), r2, cutoff2, r0ij, rrij, c6ij, t6, t8, d6, d8, edisp, gdisp real(wp) :: dE, dG(3), dS(3, 3), rb, ab cutoff2 = cutoff*cutoff !$omp parallel do schedule(runtime) default(none) & !$omp reduction(+:energy, gradient, sigma, dEdcn) & !$omp shared(mol, self, c6, dc6dcn, trans, cutoff2, r4r2) & !$omp private(iat, jat, izp, jzp, jtr, vec, r2, r0ij, rrij, c6ij, t6, t8, & !$omp& d6, d8, edisp, gdisp, dE, dG, dS, rb, ab) do iat = 1, mol%nat izp = mol%id(iat) do jat = 1, iat jzp = mol%id(jat) rrij = 3*r4r2(izp)*r4r2(jzp) r0ij = self%a1 * sqrt(rrij) + self%a2 c6ij = c6(jat, iat) do jtr = 1, size(trans, 2) vec(:) = mol%xyz(:, iat) - (mol%xyz(:, jat) + trans(:, jtr)) r2 = vec(1)*vec(1) + vec(2)*vec(2) + vec(3)*vec(3) if (r2 > cutoff2 .or. r2 < epsilon(1.0_wp)) cycle rb = r2**(self%bet*0.5_wp) ab = r0ij**self%bet t6 = rb/(rb*r2**3 + ab*r0ij**6) t8 = rb/(rb*r2**4 + ab*r0ij**8) d6 = -6*r2**2*t6**2 + self%bet*ab*r0ij**6 * t6**2 / (rb*r2) d8 = -8*r2**3*t8**2 + self%bet*ab*r0ij**8 * t8**2 / (rb*r2) edisp = self%s6*t6 + self%s8*rrij*t8 gdisp = self%s6*d6 + self%s8*rrij*d8 dE = -c6ij*edisp * 0.5_wp dG(:) = -c6ij*gdisp*vec dS(:, :) = spread(dG, 1, 3) * spread(vec, 2, 3) * 0.5_wp energy(iat) = energy(iat) + dE dEdcn(iat) = dEdcn(iat) - dc6dcn(iat, jat) * edisp sigma(:, :) = sigma + dS if (iat /= jat) then energy(jat) = energy(jat) + dE dEdcn(jat) = dEdcn(jat) - dc6dcn(jat, iat) * edisp gradient(:, iat) = gradient(:, iat) + dG gradient(:, jat) = gradient(:, jat) - dG sigma(:, :) = sigma + dS end if end do end do end do end subroutine get_dispersion_derivs !> Evaluation of the dispersion energy expression subroutine get_dispersion3(self, mol, trans, cutoff, rvdw, r4r2, c6, dc6dcn, & & energy, dEdcn, gradient, sigma) !> Damping parameters class(optimizedpower_damping_param), intent(in) :: self !> Molecular structure data class(structure_type), intent(in) :: mol !> Lattice points real(wp), intent(in) :: trans(:, :) !> Real space cutoff real(wp), intent(in) :: cutoff !> Van-der-Waals radii for damping function real(wp), intent(in) :: rvdw(:, :) !> Expectation values for C8 extrapolation real(wp), intent(in) :: r4r2(:) !> C6 coefficients for all atom pairs. real(wp), intent(in) :: c6(:, :) !> Derivative of the C6 w.r.t. the coordination number real(wp), intent(in), optional :: dc6dcn(:, :) !> Dispersion energy real(wp), intent(inout) :: energy(:) !> Derivative of the energy w.r.t. the coordination number real(wp), intent(inout), optional :: dEdcn(:) !> Dispersion gradient real(wp), intent(inout), optional :: gradient(:, :) !> Dispersion virial real(wp), intent(inout), optional :: sigma(:, :) call get_atm_dispersion(mol, trans, cutoff, self%s9, rs9, self%alp+2, & & rvdw, c6, dc6dcn, energy, dEdcn, gradient, sigma) end subroutine get_dispersion3 !> Evaluation of the dispersion energy expression projected on atomic pairs subroutine get_pairwise_dispersion2(self, mol, trans, cutoff, rvdw, r4r2, c6, energy) !> Damping parameters class(optimizedpower_damping_param), intent(in) :: self !> Molecular structure data class(structure_type), intent(in) :: mol !> Lattice points real(wp), intent(in) :: trans(:, :) !> Real space cutoff real(wp), intent(in) :: cutoff !> Van-der-Waals radii for damping function real(wp), intent(in) :: rvdw(:, :) !> Expectation values for r4 over r2 operator real(wp), intent(in) :: r4r2(:) !> C6 coefficients for all atom pairs. real(wp), intent(in) :: c6(:, :) !> Dispersion energy real(wp), intent(inout) :: energy(:, :) integer :: iat, jat, izp, jzp, jtr real(wp) :: vec(3), r2, cutoff2, r0ij, rrij, c6ij, t6, t8, edisp, dE, rb, ab cutoff2 = cutoff*cutoff !$omp parallel do schedule(runtime) default(none) shared(energy) & !$omp shared(mol, self, c6, trans, cutoff2, r4r2) private(iat, jat, izp, jzp, & !$omp& jtr, vec, r2, r0ij, rrij, c6ij, t6, t8, edisp, dE, rb, ab) do iat = 1, mol%nat izp = mol%id(iat) do jat = 1, iat jzp = mol%id(jat) rrij = 3*r4r2(izp)*r4r2(jzp) r0ij = self%a1 * sqrt(rrij) + self%a2 c6ij = c6(jat, iat) do jtr = 1, size(trans, 2) vec(:) = mol%xyz(:, iat) - (mol%xyz(:, jat) + trans(:, jtr)) r2 = vec(1)*vec(1) + vec(2)*vec(2) + vec(3)*vec(3) if (r2 > cutoff2 .or. r2 < epsilon(1.0_wp)) cycle rb = r2**(self%bet*0.5_wp) ab = r0ij**self%bet t6 = rb/(rb*r2**3 + ab*r0ij**6) t8 = rb/(rb*r2**4 + ab*r0ij**8) edisp = self%s6*t6 + self%s8*rrij*t8 dE = -c6ij*edisp * 0.5_wp !$omp atomic energy(jat, iat) = energy(jat, iat) + dE if (iat /= jat) then !$omp atomic energy(iat, jat) = energy(iat, jat) + dE end if end do end do end do end subroutine get_pairwise_dispersion2 !> Evaluation of the dispersion energy expression subroutine get_pairwise_dispersion3(self, mol, trans, cutoff, rvdw, r4r2, c6, energy) !> Damping parameters class(optimizedpower_damping_param), intent(in) :: self !> Molecular structure data class(structure_type), intent(in) :: mol !> Lattice points real(wp), intent(in) :: trans(:, :) !> Real space cutoff real(wp), intent(in) :: cutoff !> Van-der-Waals radii for damping function real(wp), intent(in) :: rvdw(:, :) !> Expectation values for r4 over r2 operator real(wp), intent(in) :: r4r2(:) !> C6 coefficients for all atom pairs. real(wp), intent(in) :: c6(:, :) !> Dispersion energy real(wp), intent(inout) :: energy(:, :) call get_atm_pairwise_dispersion(mol, trans, cutoff, self%s9, rs9, self%alp+2, & & rvdw, c6, energy) end subroutine get_pairwise_dispersion3 end module dftd3_damping_optimizedpower