dftd3_mpi Module

MPI aware entry points of the dispersion calculation.

Every rank holds the complete structure, evaluates the share of the interaction loops assigned to its rank and the results are reduced over the communicator. All routines report the missing feature in the error handler if s-dftd3 was built without MPI support, see dftd3_feature.


Uses


Interfaces

public interface get_dispersion_mpi

Calculate dispersion energy distributed over an MPI communicator

  • private subroutine get_dispersion_mpi_atomic(error, mol, disp, param, cutoff, comm, energies, gradient, sigma, hessian)

    Calculate atom-resolved dispersion energies distributed over a communicator

    Arguments

    Type IntentOptional Attributes Name
    type(error_type), intent(out), allocatable :: error

    Error handling
    class(structure_type), intent(in) :: mol

    Molecular structure data
    class(d3_model), intent(in) :: disp

    Dispersion model
    class(damping_param), intent(in) :: param

    Damping parameters
    type(realspace_cutoff), intent(in) :: cutoff

    Realspace cutoffs
    integer, intent(in) :: comm

    MPI communicator handle, users of mpi_f08 pass comm%mpi_val
    real(kind=wp), intent(out), contiguous :: energies(:)

    Dispersion energy
    real(kind=wp), intent(out), optional, contiguous :: gradient(:,:)

    Dispersion gradient
    real(kind=wp), intent(out), optional, contiguous :: sigma(:,:)

    Dispersion virial
    real(kind=wp), intent(out), optional, contiguous :: hessian(:,:)

    Dispersion hessian

  • private subroutine get_dispersion_mpi_scalar(error, mol, disp, param, cutoff, comm, energy, gradient, sigma, hessian)

    Calculate scalar dispersion energy distributed over a communicator

    Arguments

    Type IntentOptional Attributes Name
    type(error_type), intent(out), allocatable :: error

    Error handling
    class(structure_type), intent(in) :: mol

    Molecular structure data
    class(d3_model), intent(in) :: disp

    Dispersion model
    class(damping_param), intent(in) :: param

    Damping parameters
    type(realspace_cutoff), intent(in) :: cutoff

    Realspace cutoffs
    integer, intent(in) :: comm

    MPI communicator handle, users of mpi_f08 pass comm%mpi_val
    real(kind=wp), intent(out) :: energy

    Dispersion energy
    real(kind=wp), intent(out), optional, contiguous :: gradient(:,:)

    Dispersion gradient
    real(kind=wp), intent(out), optional, contiguous :: sigma(:,:)

    Dispersion virial
    real(kind=wp), intent(out), optional, contiguous :: hessian(:,:)

    Dispersion hessian

Subroutines

public subroutine get_counterpoise_mpi(error, mol, param, cutoff, comm, energy, gradient, sigma, hessian)

Calculate the geometric counterpoise correction distributed over a communicator

Arguments

Type IntentOptional Attributes Name
type(error_type), intent(out), allocatable :: error

Error handling
class(structure_type), intent(in) :: mol

Molecular structure data
type(gcp_param), intent(in) :: param

Geometric counterpoise parameters
type(realspace_cutoff), intent(in) :: cutoff

Realspace cutoffs
integer, intent(in) :: comm

MPI communicator handle, users of mpi_f08 pass comm%mpi_val
real(kind=wp), intent(out) :: energy

Counter-poise energy
real(kind=wp), intent(out), optional, contiguous :: gradient(:,:)

Counter-poise gradient
real(kind=wp), intent(out), optional, contiguous :: sigma(:,:)

Counter-poise virial
real(kind=wp), intent(out), optional, contiguous :: hessian(:,:)

Counter-poise hessian

public subroutine new_mpi_work_partition(error, partition, comm)

Create the work partition of the calling rank in a communicator

Arguments

Type IntentOptional Attributes Name
type(error_type), intent(out), allocatable :: error

Error handling
type(work_partition), intent(out) :: partition

New work partition
integer, intent(in) :: comm

MPI communicator handle, users of mpi_f08 pass comm%mpi_val