Line data    Source code

       1              : !--------------------------------------------------------------------------------------------------!
       2              : !   CP2K: A general program to perform molecular dynamics simulations                              !
       3              : !   Copyright 2000-2026 CP2K developers group <https://cp2k.org>                                   !
       4              : !                                                                                                  !
       5              : !   SPDX-License-Identifier: GPL-2.0-or-later                                                      !
       6              : !--------------------------------------------------------------------------------------------------!
       7              : 
       8              : MODULE xc_gauxc_gradient_policy
       9              :    IMPLICIT NONE
      10              :    PRIVATE
      11              : 
      12              : #if defined(__GAUXC) && defined(__GAUXC_ONEDFT_GRADIENT_FIX)
      13              :    LOGICAL, PARAMETER :: gauxc_has_onedft_gradient_fix = .TRUE.
      14              : #else
      15              :    LOGICAL, PARAMETER :: gauxc_has_onedft_gradient_fix = .FALSE.
      16              : #endif
      17              : 
      18              :    PUBLIC :: gauxc_has_onedft_gradient_fix, gauxc_resolve_gradient_policy
      19              : 
      20              : CONTAINS
      21              : 
      22              : ! **************************************************************************************************
      23              : !> \brief Select molecular XC gradients without changing the energy/VXC runtime.
      24              : !> \param need_gradient Whether forces or a molecular virial are requested
      25              : !> \param gapw_method Whether the calculation uses GAPW or GAPW_XC
      26              : !> \param max_l Largest angular momentum in the basis
      27              : !> \param is_model Whether a OneDFT model is used
      28              : !> \param nranks Size of the force-evaluation communicator
      29              : !> \param energy_self Whether energy/VXC uses replicated rank-local runtimes
      30              : !> \param runtime Requested AUTO, SELF or MPI gradient runtime
      31              : !> \param force_fd Force finite differences for diagnostics
      32              : !> \param use_fd Selected finite-difference route
      33              : !> \param use_mpi Selected distributed analytical route
      34              : !> \param use_self Whether a separate rank-local gradient runtime is required
      35              : !> \param error Zero on success; nonzero for an unsupported explicit request
      36              : ! **************************************************************************************************
      37           82 :    PURE SUBROUTINE gauxc_resolve_gradient_policy(need_gradient, gapw_method, max_l, is_model, nranks, &
      38              :                                                  energy_self, runtime, force_fd, use_fd, use_mpi, use_self, error)
      39              :       LOGICAL, INTENT(IN)                                :: need_gradient, gapw_method
      40              :       INTEGER, INTENT(IN)                                :: max_l
      41              :       LOGICAL, INTENT(IN)                                :: is_model
      42              :       INTEGER, INTENT(IN)                                :: nranks
      43              :       LOGICAL, INTENT(IN)                                :: energy_self
      44              :       CHARACTER(LEN=*), INTENT(IN)                       :: runtime
      45              :       LOGICAL, INTENT(IN)                                :: force_fd
      46              :       LOGICAL, INTENT(OUT)                               :: use_fd, use_mpi, use_self
      47              :       INTEGER, INTENT(OUT)                               :: error
      48              : 
      49           82 :       use_fd = .FALSE.
      50           82 :       use_mpi = .FALSE.
      51           82 :       use_self = .FALSE.
      52           82 :       error = 0
      53           82 :       IF (.NOT. need_gradient) RETURN
      54              : 
      55              :       ! PR #222 fixes OneDFT, not the separate conventional-functional path.
      56              :       use_fd = force_fd .OR. (gapw_method .AND. max_l > 3 .AND. &
      57           14 :                               .NOT. (is_model .AND. gauxc_has_onedft_gradient_fix))
      58           14 :       IF (.NOT. is_model .OR. nranks <= 1) RETURN
      59              : 
      60            2 :       SELECT CASE (runtime)
      61              :       CASE ("AUTO")
      62            2 :          use_mpi = gauxc_has_onedft_gradient_fix .AND. .NOT. energy_self .AND. .NOT. use_fd
      63            4 :          use_self = .NOT. energy_self .AND. .NOT. use_mpi .AND. .NOT. use_fd
      64              :       CASE ("SELF")
      65            6 :          use_self = .NOT. energy_self .AND. .NOT. use_fd
      66              :       CASE ("MPI")
      67            0 :          IF (.NOT. gauxc_has_onedft_gradient_fix) THEN
      68              :             error = 1
      69            0 :          ELSE IF (energy_self) THEN
      70            0 :             error = 2
      71            0 :          ELSE IF (use_fd) THEN
      72            0 :             error = 3
      73              :          ELSE
      74            0 :             use_mpi = .TRUE.
      75              :          END IF
      76              :       CASE DEFAULT
      77            8 :          error = 4
      78              :       END SELECT
      79              :    END SUBROUTINE gauxc_resolve_gradient_policy
      80              : 
      81              : END MODULE xc_gauxc_gradient_policy