cp2k.F

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!--------------------------------------------------------------------------------------------------!
!   CP2K: A general program to perform molecular dynamics simulations                              !
!   Copyright 2000-2026 CP2K developers group <https://cp2k.org>                                   !
!                                                                                                  !
!   SPDX-License-Identifier: GPL-2.0-or-later                                                      !
!--------------------------------------------------------------------------------------------------!
 
! **************************************************************************************************
!> \brief Main program of CP2K
!> \par Copyright
!>    CP2K: A general program to perform molecular dynamics simulations
!>    Copyright (C) 2000, 2001, 2002, 2003  CP2K developers group
!>    Copyright (C) 2004, 2005, 2006, 2007  CP2K developers group
!>    Copyright (C) 2008, 2009, 2010, 2011  CP2K developers group
!>    Copyright (C) 2012, 2013, 2014, 2015  CP2K developers group
!>    Copyright (C) 2016                    CP2K developers group
!> \par
!>    This program is free software; you can redistribute it and/or modify
!>    it under the terms of the GNU General Public License as published by
!>    the Free Software Foundation; either version 2 of the License, or
!>    (at your option) any later version.
!> \par
!>    This program 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 General Public License for more details.
!> \par
!>    You should have received a copy of the GNU General Public License
!>    along with this program; if not, write to the Free Software
!>    Foundation, Inc., 51 Franklin Street, Fifth Floor,
!>    Boston, MA  02110-1301, USA.
!> \par
!>    See also https://www.fsf.org/licensing/licenses/gpl.html
!> \par
!>    CP2K, including its sources and pointers to the authors
!>    can be found at  https://www.cp2k.org/
!> \note
!>       should be kept as lean as possible.
!>       see cp2k_run for more comments
!> \author Joost VandeVondele
! **************************************************************************************************
PROGRAM cp2k
 
   USE omp_lib,                         ONLY: omp_get_max_threads,&
                                              omp_set_num_threads
   USE cp2k_info,                       ONLY: compile_revision,&
                                              cp2k_flags,&
                                              cp2k_version,&
                                              print_cp2k_license
   USE cp2k_runs,                       ONLY: run_input,&
                                              write_xml_file
   USE cp2k_shell,                      ONLY: launch_cp2k_shell
   USE f77_interface,                   ONLY: check_input,&
                                              default_para_env,&
                                              finalize_cp2k,&
                                              init_cp2k
   USE input_cp2k,                      ONLY: create_cp2k_root_section
   USE input_section_types,             ONLY: section_release,&
                                              section_type
   USE iso_c_binding,                   ONLY: c_null_char
   USE iso_fortran_env,                 ONLY: compiler_options,&
                                              compiler_version
   USE kinds,                           ONLY: default_path_length
   USE machine,                         ONLY: default_error_unit,&
                                              default_output_unit,&
                                              m_cpuid,&
                                              m_cpuid_name,&
                                              m_cpuid_static,&
                                              m_cpuid_vlen
#include "../base/base_uses.f90"
 
   IMPLICIT NONE
 
   CHARACTER(LEN=default_path_length)   :: input_file_name, output_file_name, &
                                           arg_att, command
   CHARACTER(LEN=default_path_length), &
      DIMENSION(:, :), ALLOCATABLE      :: initial_variables, initial_variables_tmp
   CHARACTER(LEN=:), ALLOCATABLE        :: compiler_options_string
   INTEGER                              :: cpuid, cpuid_static, output_unit, l, i, var_set_sep, inp_var_idx
   INTEGER                              :: ierr, i_arg
   LOGICAL                              :: check, usage, echo_input, command_line_error
   LOGICAL                              :: run_it, force_run, has_input, xml, print_version, print_license, shell_mode
   TYPE(section_type), POINTER          :: input_declaration
 
   NULLIFY (input_declaration)
 
   ! output goes to the screen by default
   output_unit = default_output_unit
 
   ! set default behaviour for the command line switches
   check = .false.
   usage = .false.
   echo_input = .false.
   has_input = .false.
   run_it = .true.
   shell_mode = .false.
   force_run = .false.
   print_version = .false.
   print_license = .false.
   command_line_error = .false.
   xml = .false.
   input_file_name = "Missing input file name" ! no default
   output_file_name = "__STD_OUT__" ! by default we go to std_out
   ALLOCATE (initial_variables(2, 1:0))
 
   ! Get command and strip path
   CALL get_command_argument(number=0, VALUE=command, status=ierr)
   cpassert(ierr == 0)
   l = len_trim(command)
   DO i = l, 1, -1
      IF (command(i:i) == "/" .OR. command(i:i) == "\") EXIT
   END DO
   command = command(i + 1:l)
 
   ! Consider output redirection
   i_arg = 0
   DO WHILE (i_arg < command_argument_count())
      i_arg = i_arg + 1
      CALL get_command_argument(number=i_arg, VALUE=arg_att, status=ierr)
      cpassert(ierr == 0)
      SELECT CASE (arg_att)
      CASE ("-o")
         IF (output_file_name == "__STD_OUT__") THEN
            ! Consider only the first -o flag
            i_arg = i_arg + 1
            CALL get_command_argument(number=i_arg, VALUE=arg_att, status=ierr)
            cpassert(ierr == 0)
            IF (arg_att(1:1) == "-") THEN
               WRITE (output_unit, "(/,T2,A)") &
                  "ERROR: The output file name "//trim(arg_att)//" starts with -"
               command_line_error = .true.
            ELSE
               output_file_name = arg_att
               ! Redirect the standard output (default_output_unit) to the output file
               OPEN (unit=output_unit, file=trim(output_file_name), status="UNKNOWN", &
                     form="FORMATTED", action="WRITE", position="APPEND", iostat=ierr)
               IF (ierr /= 0) THEN
                  ! The standard output might not be connected anymore
                  WRITE (default_error_unit, "(/,T2,A)") &
                     "ERROR: The output file "//trim(output_file_name)//" cannot be opened"
                  command_line_error = .true.
               END IF
            END IF
         ELSE
            i_arg = i_arg + 1
            WRITE (output_unit, "(/,T2,A)") &
               "ERROR: The command line flag -o has been specified multiple times"
            command_line_error = .true.
         END IF
      END SELECT
   END DO
 
   ! Check if binary was invoked as cp2k_shell
   IF (command(1:10) == "cp2k_shell") THEN
      shell_mode = .true.
      run_it = .false.
   ELSE IF (command_argument_count() < 1) THEN
      WRITE (output_unit, "(/,T2,A)") &
         "ERROR: At least one command line argument must be specified"
      command_line_error = .true.
   END IF
 
   ! Check if binary was invoked as sopt or popt alias
   l = len_trim(command)
   IF (l >= 5) THEN
      IF (command(l - 4:l) == ".sopt" .OR. command(l - 4:l) == ".popt") THEN
         CALL omp_set_num_threads(1)
      END IF
   END IF
 
#ifdef __ACCELERATE
   IF (omp_get_max_threads() > 1) THEN
      block
         CHARACTER(len=default_path_length) :: env_var
         INTEGER :: veclib_max_threads, ierr
         CALL get_environment_variable("VECLIB_MAXIMUM_THREADS", env_var, status=ierr)
         veclib_max_threads = 0
         IF (ierr == 0) THEN
            READ (env_var, *) veclib_max_threads
         END IF
         IF (ierr == 1 .OR. (ierr == 0 .AND. veclib_max_threads > 1)) THEN
            CALL cp_warn(__location__, &
                         "macOS' Accelerate framework has its own threading enabled which may interfere"// &
                         " with the OpenMP threading. You can disable the Accelerate threading by setting"// &
                         " the environment variable VECLIB_MAXIMUM_THREADS=1")
         END IF
      END block
   END IF
#endif
 
   i_arg = 0
   arg_loop: DO WHILE (i_arg < command_argument_count())
      i_arg = i_arg + 1
      CALL get_command_argument(i_arg, arg_att, status=ierr)
      cpassert(ierr == 0)
      SELECT CASE (arg_att)
      CASE ("--check", "-c")
         check = .true.
         run_it = .false.
         echo_input = .false.
      CASE ("--echo", "-e")
         check = .true.
         run_it = .false.
         echo_input = .true.
      CASE ("-v", "--version")
         print_version = .true.
         run_it = .false.
      CASE ("--license")
         print_license = .true.
         run_it = .false.
      CASE ("--run", "-r")
         force_run = .true.
      CASE ("--shell", "-s")
         shell_mode = .true.
         run_it = .false.
      CASE ("-help", "--help", "-h")
         usage = .true.
         run_it = .false.
      CASE ("-i")
         i_arg = i_arg + 1
         CALL get_command_argument(i_arg, arg_att, status=ierr)
         cpassert(ierr == 0)
         ! argument does not start with a - it is an filename
         IF (.NOT. arg_att(1:1) == "-") THEN
            input_file_name = arg_att
            has_input = .true.
         ELSE
            WRITE (output_unit, "(/,T2,A)") &
               "ERROR: The input file name "//trim(arg_att)//" starts with -"
            command_line_error = .true.
            EXIT arg_loop
         END IF
      CASE ("-E", "--set")
         i_arg = i_arg + 1
         CALL get_command_argument(i_arg, arg_att, status=ierr)
         cpassert(ierr == 0)
 
         var_set_sep = index(arg_att, '=')
 
         IF (var_set_sep < 2) THEN
            WRITE (output_unit, "(/,T2,A)") "ERROR: Invalid initializer for preprocessor variable: "//trim(arg_att)
            command_line_error = .true.
            EXIT arg_loop
         END IF
 
         DO inp_var_idx = 1, SIZE(initial_variables, 2)
            ! check whether the variable was already set, in this case, overwrite
            IF (trim(initial_variables(1, inp_var_idx)) == arg_att(:var_set_sep - 1)) THEN
               EXIT
            END IF
         END DO
 
         IF (inp_var_idx > SIZE(initial_variables, 2)) THEN
            ! if the variable was never set before, extend the array
            ALLOCATE (initial_variables_tmp(2, SIZE(initial_variables, 2) + 1))
            initial_variables_tmp(:, 1:SIZE(initial_variables, 2)) = initial_variables
            CALL move_alloc(initial_variables_tmp, initial_variables)
         END IF
 
         initial_variables(1, inp_var_idx) = arg_att(:var_set_sep - 1)
         initial_variables(2, inp_var_idx) = arg_att(var_set_sep + 1:)
      CASE ("-o")
         ! Skip -o flag which have been processed already
         i_arg = i_arg + 1
         CALL get_command_argument(i_arg, arg_att, status=ierr)
         cpassert(ierr == 0)
         IF (arg_att(1:1) == "-") EXIT arg_loop
      CASE ("--xml")
         xml = .true.
         run_it = .false.
      CASE DEFAULT
         ! if the last argument does not start with a - it is an input filename
         !MK in order to digest the additional flags of mpirun
         IF ((.NOT. has_input) .AND. &
             (i_arg == command_argument_count()) .AND. &
             (.NOT. arg_att(1:1) == "-")) THEN
            input_file_name = arg_att
            has_input = .true.
         ELSE IF (has_input .AND. &
                  (.NOT. arg_att(1:1) == "-")) THEN
            WRITE (output_unit, "(/,T2,A)") &
               "Error: Tried to specify two input files"
            command_line_error = .true.
            EXIT arg_loop
         END IF
      END SELECT
   END DO arg_loop
 
   IF ((run_it .OR. force_run .OR. check .OR. echo_input) .AND. &
       (.NOT. has_input) .AND. (.NOT. command_line_error)) THEN
      WRITE (unit=output_unit, fmt="(/,T2,A)") &
         "ERROR: An input file name is required"
      command_line_error = .true.
   END IF
 
   CALL init_cp2k(init_mpi=.true., ierr=ierr)
 
   IF (ierr == 0) THEN
      ! some first info concerning how to run CP2K
 
      IF (usage .OR. command_line_error) THEN
         IF (default_para_env%is_source()) THEN
            l = len_trim(command)
            WRITE (unit=output_unit, fmt="(/,(T2,A))") &
               trim(command)//" [-c|--check] [-e|--echo] [-h|--help]", &
               repeat(" ", l)//" [-i] <input_file>", &
               repeat(" ", l)//" [-mpi-mapping|--mpi-mapping] <method>", &
               repeat(" ", l)//" [-o] <output_file>", &
               repeat(" ", l)//" [-r|-run] [-s|--shell] [--xml]"
            WRITE (unit=output_unit, fmt="(/,T2,A,/,/,T2,A,/,/,T2,A,/,/,(T3,A))") &
               "starts the CP2K program, see <https://www.cp2k.org/>", &
               "The easiest way is "//trim(command)//" <input_file>", &
               "The following options can be used:", &
               "-i <input_file>      : provides an input file name, if it is the last", &
               "                       argument, the -i flag is not needed", &
               "-o <output_file>     : provides an output file name [default: screen]"
            WRITE (unit=output_unit, fmt="(/,T2,A,/,/,(T3,A))") &
               "These switches skip the simulation, unless [-r|-run] is specified:", &
               "--check, -c          : performs a syntax check of the <input_file>", &
               "--echo, -e           : echoes the <input_file>, and make all defaults explicit", &
               "                       The input is also checked, but only a failure is reported", &
               "--help, -h           : writes this message", &
               "--license            : prints the CP2K license", &
               "--mpi-mapping        : applies a given MPI reordering to CP2K", &
               "--run, -r            : forces a CP2K run regardless of other specified flags", &
               "--shell, -s          : start interactive shell mode", &
               "--version, -v        : prints the CP2K version and the revision number", &
               "--xml                : dumps the whole CP2K input structure as a XML file", &
               "                       xml2htm generates a HTML manual from this XML file", &
               "--set, -E name=value : set the initial value of a preprocessor value", &
               ""
         END IF
      END IF
 
      IF (.NOT. command_line_error) THEN
 
         ! write the version string
         IF (print_version) THEN
            IF (default_para_env%is_source()) THEN
               WRITE (output_unit, "(T2,A)") cp2k_version, &
                  "Source code revision "//trim(compile_revision), &
                  trim(cp2k_flags())
               ! The trailing NUL character bounds the in-place prefix replacement of
               ! package managers like conda to this string, which would otherwise
               ! shift and corrupt the subsequent string literals in the binary
               compiler_options_string = compiler_options()//c_null_char
               l = index(compiler_options_string, c_null_char) - 1
               WRITE (output_unit, "(T2,A,A)") "compiler: ", compiler_version()
               cpuid = m_cpuid()
               cpuid_static = m_cpuid_static()
               IF ((cpuid > 0) .OR. (cpuid_static > 0)) THEN
                  WRITE (output_unit, "(T2,A,1X,I6,1X,A)") &
                     "compiler target: cpuid", cpuid_static, "("//trim(m_cpuid_name(cpuid_static))//")"
                  IF (cpuid /= cpuid_static) THEN
                     WRITE (output_unit, "(T2,A,1X,I6,1X,A)") &
                        "current: cpuid", cpuid, "("//trim(m_cpuid_name(cpuid))//")"
                  END IF
               END IF
               IF (m_cpuid_vlen(cpuid_static) < m_cpuid_vlen(cpuid)) THEN
                  WRITE (output_unit, "(T2,A)") &
                     "WARNING: The compiler target used to build this binary does not "// &
                     "enable all instruction-set extensions available on this CPU. "// &
                     "Consider reconfiguring and rebuilding CP2K for this target system "// &
                     "to enable them."
               END IF
               WRITE (output_unit, "(T2,A)") "compiler options:"
               DO i = 0, (l - 1)/68
                  WRITE (output_unit, "(T4,A)") &
                     compiler_options_string(i*68 + 1:min(l, (i + 1)*68))
               END DO
               DEALLOCATE (compiler_options_string)
            END IF
         END IF
 
         ! write the license
         IF (print_license) THEN
            IF (default_para_env%is_source()) THEN
               CALL print_cp2k_license(output_unit)
            END IF
         END IF
 
         IF (xml) THEN
            IF (default_para_env%is_source()) THEN
               CALL write_xml_file()
            END IF
         END IF
 
         CALL create_cp2k_root_section(input_declaration)
 
         IF (check) THEN
            CALL check_input(input_declaration, input_file_name, output_file_name, &
                             echo_input=echo_input, ierr=ierr, initial_variables=initial_variables)
            IF (default_para_env%is_source()) THEN
               IF (ierr == 0) THEN
                  IF (.NOT. echo_input) THEN
                     WRITE (output_unit, "(A)") "SUCCESS, the input could be parsed correctly."
                     WRITE (output_unit, "(A)") "         This does not guarantee that this input is meaningful"
                     WRITE (output_unit, "(A)") "         or will run successfully"
                  END IF
               ELSE
                  WRITE (output_unit, "(A)") "ERROR,   the input could *NOT* be parsed correctly."
                  WRITE (output_unit, "(A)") "         Please, check and correct it"
               END IF
            END IF
         END IF
 
         IF (shell_mode) THEN
            CALL launch_cp2k_shell(input_declaration)
         END IF
 
         IF (run_it .OR. force_run) THEN
            CALL run_input(input_declaration, input_file_name, output_file_name, initial_variables)
         END IF
 
         CALL section_release(input_declaration)
      END IF
   ELSE
      WRITE (unit=output_unit, fmt="(/,A)") "initial setup (MPI ?) error"
   END IF
 
   ! and the final cleanup
   CALL finalize_cp2k(finalize_mpi=.true., ierr=ierr)
   DEALLOCATE (initial_variables)
   cpassert(ierr == 0)
 
END PROGRAM cp2k