cif_dft_0.032.dic

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#$Date$
#$Revision$
#$URL$
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# This file is available in the Theoretical Crystallography Open
# Database (TCOD), http://www.crystallography.net/tcod/cif/dictionaries/.
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# This file is designated by the authors and the contributors
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data_on_this_dictionary
    _dictionary_name            cif_dft.dic
    _dictionary_version         0.032
    _dictionary_update          2023-11-15
    _dictionary_history
;
2023-11-15 Adding missing category definitions. A.M.

2019-05-14 Making '_dft_XC_functional_[]' a category. Specifying categories
           for all data items lacking them. A.M.

2019-03-19 Setting _list_reference of
           '_dft_BZ_integration_grid_IBZ_point_weight' to
           '_dft_BZ_integration_grid_IBZ_point_id' instead of itself. A.M.

2019-03-18 Declaring all data items of category 'dft_pseudopotential' as
           looped. Adding '_units_detail' for all data items with units.
           A.M.

2018-02-05 Putting '_dft_kinetic_energy_cutoff_*', '_dft_alloy_*' and
           '_dft_atom_type_*' data items into separate categories.
           Improving descriptions for the values of
           '_dft_pseudopotential_type'. Fixing links to categories
           'dft_basisset' and 'dft_BZ_integration'. A.M.

2018-02-01 Putting Brillouin zone integration-related data items into a
           separate category. A.M.

2017-01-04 Redefining tag '_dft_cell_pressure' as numeric. Defining units
           of '_dft_cell_pressure' as kPa. A.M.

2016-11-10 Allowing tags '_dft_pseudopotential_*' in loops, adding tag
           '_dft_pseudopotential_atom_type' to link to
           '_atom_site_type_symbol', thus allowing specification of
           per-atom-type pseudopotentials. A.M.

2016-04-13 Adding enumeration value 'daubechies' for _dft_basisset_type 
           matching same value in ETSF specification. A.M.

2016-03-14 Adding _dft_dielectric_constant. A.M.

2016-02-19 Redefining tags _dft_BZ_integration_smearing_width and
           _dft_atom_type_valence_electrons as numeric. A.M.

2016-02-09 Adding _dft_band_gap. Fixing 'ev' -> 'eV' as units of
           _dft_atom_relax_force_conv (typo). A.M.

2016-01-22 Redefining tag _dft_cell_magn_moment as numeric with units of
           \m_B. A.M.

2015-10-16 Redefining units of _dft_bulk_modulus as gigapascals. A.M.

2015-10-15 Adding data names _dft_stiffness_tensor_* for stiffness tensor
           matrix representation. Marking _dft_basisset_[] as category.
           A.M.

2015-10-02 Adding data names _dft_lattice_energy and _dft_bulk_modulus.
           Redefining units of _dft_bulk_modulus to kilopascals,
           _dft_lattice_energy to kilojoules per mole. A.M.

2015-09-14 Fixing data name in data_dft_atom_basisset_citation_id: was
           _dft_basisset_citation_id (duplicate of one defined in
           data_dft_basisset_citation_id), should be
           _dft_atom_basisset_citation_id. A.M.

2015-08-03 Adding data names _dft_kinetic_energy_cutoff_*. A.M.

2015-07-29 Adding descriptions for abbreviated enumeration values for
           _dft_XC_functional_type, _dft_pseudopotential_type and
           _dft_alloy_method. A.M.

2015-07-21 Redefining values of _dft_BZ_integration_method as
           enumeration values. Adding tag
           _dft_BZ_integration_method_other_name. Redefining tags
           _dft_BZ_integration_grid_shift_[XYZ] as numbers with values
           from a range [0:1]. A.M.

2015-07-20 Adding data names for listing points in irreducible Brillouin
           zone as well as data names to define smearing method for
           Brillouin zone integration. A.M.

2015-05-07 Redefining values of _dft_BZ_integration_MP_order as numeric
           with a range [0,+Inf). Adding a description. A.M.

2015-01-09 Adding data names for Ewald, Fermi and Hartree energy terms.
           A.M.

2014-11-04 Consolidating all DFT related data names into this
           dictionary, elaborating basis set definition, adding
           citation ling data items. S.G.

2013-08-17 Adding two additional data names to describe custom names of
           alloy methods and XC functional types if their enumerator 
           values are givem as 'other'. S.G.

2013-08-17 Adding all datanames from Bj\"orkman Torbj\"orn's 2013-05-09
           11:23 e-mail. S.G.

2013-08-17 Adding an empty CIF scaffold for the DFT dictionary. S.G.
;

###############################################################################
# XC (exchange-correlation) functional
###############################################################################

data_dft_XC_functional_[]
    _name '_dft_XC_functional_[]'
    _category category_overview
    _type null
    _definition
;
  Data items in this category describe the exchange-correlation (XC) functional.
;

data_dft_XC_functional_id
    _name '_dft_XC_functional_id'
    _category dft_XC_functional
    _type char
    _definition
;
  XC functional ID in the XC functional loop (for mixed functionals). S.G.
;

data_dft_XC_exchange_functional_name
    _name '_dft_XC_exchange_functional_name'
    _category dft_XC_functional
    _type char
    _definition
;
  A very comprehensive XC functional list can be found at the NOMAD site:

  https://gitlab.rzg.mpg.de/nomad-lab/nomad-meta-info/wikis/metainfo/XC-functional

  Our dictionary should be harmonised with this list.

  The corresponding NOMAD metadata entry is 'XC_functional' and 'XC_functional_name'.

  S.G. 2016-10-28
;

data_dft_XC_exchange_functional_weight
    _name '_dft_XC_exchange_functional_weight'
    _category dft_XC_functional
    _type numb
    _definition
;
 A proportion (weight) of the particular XC exchange functional for
 mixed functionals. S.G.
;

data_dft_XC_correlation_functional_name
    _name '_dft_XC_correlation_functional_name'
    _category dft_XC_functional
    _type char
    _definition
;. . .
;

data_dft_XC_correlation_functional_weight
    _name '_dft_XC_correlation_functional_weight'
    _category dft_XC_functional
    _type numb
    _definition
;
 A proportion (weight) of the particular XC correlation functional for
 mixed functionals. S.G.
;

data_dft_XC_functional_type
    _name '_dft_XC_functional_type'
    _category dft_XC_functional
    _type char
    loop_ _enumeration
          _enumeration_detail
          LDA                    'local-density approximation'
          GGA                    'generalized gradient approximation'
          meta-GGA               'GGA with the second derivative of electron density'
          Hybrid                 'describe the corresponding functional here'
          ACFD-RPA               'describe the corresponding functional here'
          'orbital functionals'  'describe the corresponding functional here'
          'exact exchange'       'describe the corresponding functional here'
          vdW-DF                 'as proposed by Dion et al. (2004)'
          LDA/GGA+U/DMFT         'describe the corresponding functional here'
          'orbital polarization' 'describe the corresponding functional here'
          other                  'functional not one of the mentioned above'
    _definition
; Approximation for exchange-correlation functionals.
;

data_dft_XC_functional_type_other_name
    _name '_dft_XC_functional_type_other_name'
    _category dft_XC_functional
    _type char
    _definition
; Custom name of the functional if _dft_XC_functional_type data item value
  is given as 'other'.
;


data_dft_XC_functional_citation_id
    _name '_dft_XC_functional_citation_id'
    _category dft_XC_functional
    _type char
    _list_link_parent '_citation_id'
    _definition
; A reference to the citation describing the XC functional in the
_citation_... category loop
;     

###############################################################################
# Basis set.
###############################################################################

data_dft_basisset_[]
    _name '_dft_basisset_[]'
    _type null
    _category category_overview
    _definition
; Data items to describe the basis set used in the computation.
;

data_dft_basisset_type
    _name '_dft_basisset_type'
    _type char
    _category dft_basisset
    loop_
    _enumeration
    _enumeration_detail
            plane-wave 'DFT; covered by the items below? S.G.'

            orbital        'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            dftorb         'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            dftxfit        'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            dftcfit        'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            periodic       'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            ecporb         'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            spinorb        'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            polarization   'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            diffuse        'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            tight          'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            rydberg        'from http://www.xml-cml.org/dictionary/compchem/#basisSet'
            daubechies     'from http://www.etsf.eu/system/files/SpecFFETSF_v3.3.pdf'
    _definition
; Type of the basis set used in the computation.

  Should be the same data item as in
  http://www.xml-cml.org/dictionary/compchem/#basisSet. This
  corresponds to the "basisSetType" in the EMSL schema. Valid values
  are from the http://www.xml-cml.org/dictionary/compchem/ are:
        
            orbital
            dftorb
            dftxfit
            dftcfit
            periodic
            ecporb
            spinorb
            polarization
            diffuse
            tight
            rydberg

   Q: how plane wave basis set is encoded? (S.G.)
;

data_dft_basisset_energy_conv 
    _name '_dft_basisset_energy_conv'
    _type char
    _units eV
    _units_detail 'electron-Volts'
    _category dft_basisset
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
  Energy measured in eV (electron-volts).
;

data_dft_basisset_citation_id
    _name '_dft_basisset_citation_id'
    _type char
    _category dft_basisset
    _list_link_parent '_citation_id'
    _definition
; A reference to the citation describing the basis set in the
_citation_... category loop
;     

data_dft_basisset_database_name
    _name '_dft_basisset_database_name'
    _type char
    _category dft_basisset
    _definition
; A name of a database where the basis set comes from, e.g. "EMSL
  Basis Set Exchange"
;

data_dft_basisset_database_abbrev
    _name '_dft_basisset_database_abbrev'
    _type char
    _category dft_basisset
    _definition
; A name of a database where the basis set comes from, e.g. "BSE"
;

data_dft_basisset_database_code
    _name '_dft_basisset_database_code'
    _type char
    _category dft_basisset
    _definition
; A unique stable code (identifier, key) assigned to the basis set by
a database.
;

data_dft_basisset_database_URI
    _name '_dft_basisset_database_URI'
    _type char
    _category dft_basisset
    _definition
; A stable URI of the Basis set database landing page.
;

data_dft_basisset_URI
    _name '_dft_basisset_URI'
    _type char
    _category dft_basisset
    _definition
; A stable URI at which specific basis set can be retrieved.
;

data_dft_basisset_database_citation_id
    _name '_dft_basisset_database_citation_id'
    _type char
    _category dft_basisset
    _list_link_parent '_citation_id'
    _definition
; A reference to the citation describing the basis set database in the
_citation_... category loop.
;     

###############################################################################
# Atom Basis set.
###############################################################################

data_dft_atom_basisset_[]
    _name '_dft_atom_basisset_[]'
    _category category_overview
    _type null
    _definition
; Data items to describe per-atom basis sets used in the computation.
;

data_dft_atom_basisset
    _name '_dft_atom_basisset'
    _category dft_atom_basisset
    _type char
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_atom_basisset_type
    _name '_dft_atom_basisset_type'
    _category dft_atom_basisset
    _type char
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_atom_basisset_energy_conv
    _name '_dft_atom_basisset_energy_conv'
    _category dft_atom_basisset
    _type char
    _units eV
    _units_detail 'electron-Volts'
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE

  In eV.
;

data_dft_atom_basisset_citation_id
    _name '_dft_atom_basisset_citation_id'
    _category dft_atom_basisset
    _type char
    _list_link_parent '_citation_id'
    _definition
; A reference to the citation describing the atom basis set in the
_citation_... category loop
;     

###############################################################################
# Brillouin zone integration description
###############################################################################

data_dft_BZ_integration_[]
    _name '_dft_BZ_integration_[]'
    _type null
    _category category_overview
    _definition
; Data items to describe the integration of Brillouin zone (BZ).
;

data_dft_BZ_integration_method
    _name '_dft_BZ_integration_method'
    _type char
    _category dft_BZ_integration
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;
    loop_
    _enumeration
    _enumeration_detail
    'simple sampling'      'describe the corresponding method here'
    'linear tetrahedron'   'describe the corresponding method here'
    'weighted tetrahedron' 'describe the corresponding method here'
    'Monkhorst-Pack'
; As described in:
Monkhorst, H. J. & Pack, J. D.
Special points for Brillouin-zone integrations
Phys. Rev. B, American Physical Society, 1976, 13, 5188-5192
;
    'other'
; Description is provided in _dft_BZ_integration_method_other
;

data_dft_BZ_integration_method_other
    _name '_dft_BZ_integration_method_other'
    _type char
    _category dft_BZ_integration
    _definition
; Description of used BZ integration method if different from enumeration
values of _dft_BZ_integration_method.
;

data_dft_BZ_integration_citation_id
    _name '_dft_BZ_integration_citation_id'
    _type char
    _category dft_BZ_integration
    _list_link_parent '_citation_id'
    _definition
; A reference to the citation describing the BZ integration method in the
_citation_... category loop
;

data_dft_BZ_integration_grid_type
    _name '_dft_BZ_integration_grid_type'
    _type char
    _category dft_BZ_integration
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_BZ_integration_grid_[]
    loop_ _name '_dft_BZ_integration_grid_X'
                '_dft_BZ_integration_grid_Y'
                '_dft_BZ_integration_grid_Z'
    _type char
    _category dft_BZ_integration
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_BZ_integration_grid_IBZ_points
    _name '_dft_BZ_integration_grid_IBZ_points'
    _type char
    _category dft_BZ_integration
    _definition
; Number of points in irreducible BZ.
  (Please expand the explanation, especially for non-specialists).
;

data_dft_BZ_integration_grid_dens_[]
    loop_ _name
        '_dft_BZ_integration_grid_dens_X'
        '_dft_BZ_integration_grid_dens_Y'
        '_dft_BZ_integration_grid_dens_Z'
    _type char
    _category dft_BZ_integration
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_BZ_integration_grid_shift_[]
    loop_ _name
        '_dft_BZ_integration_grid_shift_X'
        '_dft_BZ_integration_grid_shift_Y'
        '_dft_BZ_integration_grid_shift_Z'
    _type numb
    _category dft_BZ_integration
    _enumeration_range 0:1
    _definition
; Shift of the integration grid to the given direction. Value is
given as a fraction of reciprocal lattice vector.
;
    _example
;
    loop_
    _dft_BZ_integration_grid_shift_X
    _dft_BZ_integration_grid_shift_Y
    _dft_BZ_integration_grid_shift_Z
    0.5 0.5 0
;
    _example_detail
; Integration grid is shifted by half of reciprocal cell vectors X and Y.
;

data_dft_BZ_integration_Froyen_map
    _name '_dft_BZ_integration_Froyen_map'
    _type char
    _category dft_BZ_integration
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_BZ_integration_smearing_method
    _name '_dft_BZ_integration_smearing_method'
    _type char
    _category dft_BZ_integration
    _definition
; The used BZ integration smearing method.
;
    loop_
    _enumeration
    _enumeration_detail
    Gaussian
; Approximation with Gaussian distribution.
;
    Fermi-Dirac
; Approximation with Fermi-Dirac function.
;
    Methfessel-Paxton
; As described in:
Methfessel, M. & Paxton, A. T.
High-precision sampling for Brillouin-zone integration in metals
Phys. Rev. B, American Physical Society, 1989, 40, 3616-3621
;
    Marzari-Vanderbilt
; As described in:
Marzari, N.; Vanderbilt, D.; De Vita, A. & Payne, M. C.
Thermal Contraction and Disordering of the Al(110)
Surface Phys. Rev. Lett., American Physical Society, 1999, 82, 3296-3299
;
    other
; Description is provided in _dft_BZ_integration_smearing_method_other.
;

data_dft_BZ_integration_smearing_method_other
    _name '_dft_BZ_integration_smearing_method_other'
    _type char
    _category dft_BZ_integration
    _definition
; Description of used BZ integration smearing method if different from
enumeration values of _dft_BZ_integration_smearing_method.
;

data_dft_BZ_integration_smearing_width
    _name '_dft_BZ_integration_smearing_width'
    _type numb
    _category dft_BZ_integration
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_BZ_integration_MP_order
    _name '_dft_BZ_integration_MP_order'
    _type numb
    _category dft_BZ_integration
    _enumeration_range 0:
    _definition
; Order of Methfessel-Paxton approximation, see PRB 40, 3616 (1989) and
http://www.hector.ac.uk/cse/distributedcse/reports/conquest/conquest/node6.html
for reference.
;

data_dft_BZ_integration_energy_conv
    _name '_dft_BZ_integration_energy_conv'
    _type char
    _category dft_BZ_integration
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

###############################################################################
# Miscellaneous settings of the calculation
###############################################################################

data_dft_cell_settings_[]
    _name '_dft_cell_settings_[]'
    _category category_overview
    _type null
    _definition
;
  Miscellaneous settings of the calculation.
;

data_dft_cell_pressure
    _name '_dft_cell_pressure'
    _category dft_cell_settings
    _type numb
    _units kPa
    _units_detail kilopascals
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_cell_periodic_BC_[]
    loop_ _name
        '_dft_cell_periodic_BC_X'
        '_dft_cell_periodic_BC_Y'
        '_dft_cell_periodic_BC_Z'
    _category dft_cell_settings
    _type char
    loop_
    _enumeration
    _enumeration_detail
    true  'Boundary condition is periodic in the given direction.'
    t     'Same as "true"'
    false
; Boundary condition is NOT periodic in the given direction (i.e. the
structure is finite in this direction).
;
    f     'Same as "false"'
    _definition
; Specifies whether periodic boundary conditions were used along each of
the unit cell axes.
;

###############################################################################
# Points in irreducible BZ
###############################################################################

data_dft_BZ_integration_grid_IBZ_point_[]
    _name '_dft_BZ_integration_grid_IBZ_point_[]'
    _category category_overview
    _type null
    _definition
;
  Data items in this category describe the irreducible Brillouin zone (IBZ).
;

data_dft_BZ_integration_grid_IBZ_point_id
    _name '_dft_BZ_integration_grid_IBZ_point_id'
    _category dft_BZ_integration_grid_IBZ_point
    _type char
    _list yes
    _list_mandatory yes
    _definition
; A unique identifier (primary key) of an irreducible BZ point in a loop.
;

data_dft_BZ_integration_grid_IBZ_point_
    loop_ _name
        '_dft_BZ_integration_grid_IBZ_point_X'
        '_dft_BZ_integration_grid_IBZ_point_Y'
        '_dft_BZ_integration_grid_IBZ_point_Z'
    _category dft_BZ_integration_grid_IBZ_point
    _type numb
    _type_conditions esd
    _list yes
    _list_reference '_dft_BZ_integration_grid_IBZ_point_id'
    _definition
; Coordinates of irreducible BZ points in relative coordinates of the
reciprocal lattice vectors.
;

data_dft_BZ_integration_grid_IBZ_point_weight
    _name '_dft_BZ_integration_grid_IBZ_point_weight'
    _category dft_BZ_integration_grid_IBZ_point
    _type numb
    _list yes
    _list_reference '_dft_BZ_integration_grid_IBZ_point_id'
    _enumeration_range 0:1
    _definition
; Normalized weights of irreducible BZ points.
;

###############################################################################
# Electron counts
###############################################################################

data_dft_cell_valence_electrons
    _name '_dft_cell_valence_electrons'
    _category dft_cell_settings
    _type numb
    _enumeration_range 1:
    _definition
; Total number of electrons in calculation.
;

data_dft_core_electrons
    _name '_dft_core_electrons'
    _category dft_cell_settings
    _type numb
    _enumeration_range 1:
    _definition
; Total number of core electrons in calculation
;

###############################################################################
# Pseudopotentials
###############################################################################

data_dft_pseudopotential_[]
    _name '_dft_pseudopotential_[]'
    _type null
    _category category_overview
    _definition
; Data items to describe used pseudopotentials.
;

data_dft_pseudopotential_atom_type
    _name '_dft_pseudopotential_atom_type'
    _type char
    _category dft_pseudopotential
    _list yes
    _list_link_parent '_atom_site_type_symbol'
    _list_mandatory yes
    _definition
; A reference to the atom type, for which the pseudopotential is used.
;
    loop_ _example
          'H'
          'Cu'

data_dft_pseudopotential_type
    _name '_dft_pseudopotential_type'
    _type char
    _category dft_pseudopotential
    _list yes
    loop_ _enumeration
          _enumeration_detail
          NCPP      'norm-conserving pseudopotential'
          USPP      'ultrasoft pseudopotential'
          PAW       'projector augmented waves pseudopotential'
          other
; description should be given in the CIF data item
  _dft_pseudopotential_type_other_name
;
    _definition
; PLEASE ADD HUMAN-READABLE DESCRIPTION HERE
  L.V. Added by L.V.
;

data_dft_pseudopotential_type_other_name
    _name '_dft_pseudopotential_type_other_name'
    _type char
    _category dft_pseudopotential
    _list yes
    _definition
; Custom name of the pseudopotential if _dft_pseudopotential_type data
  item value is given as 'other'.
;

data_dft_pseudopotential_citation_id
    _name '_dft_pseudopotential_citation_id'
    _type char
    _category dft_pseudopotential
    _list yes
    _list_link_parent '_citation_id'
    _definition
; A reference to the citation describing the pseudopotential in the
  _citation_... category loop.
;

###############################################################################
# Kinetic energy cut-offs
###############################################################################

data_dft_kinetic_energy_cutoff_[]
    _name '_dft_kinetic_energy_cutoff_[]'
    _type null
    _category category_overview
    _definition
; Data items to describe limits (cutoffs) for kinetic energy that were
used in the calculations.
;

data_dft_kinetic_energy_cutoff_wavefunctions
    _name '_dft_kinetic_energy_cutoff_wavefunctions'
    _type numb
    _units eV
    _units_detail 'electron-Volts'
    _category dft_kinetic_energy_cutoff
    _definition
; Limit of the maximum kinetic energy for wavefunctions, used to reduce
the basis set to a finite size.
;

data_dft_kinetic_energy_cutoff_charge_density
    _name '_dft_kinetic_energy_cutoff_charge_density'
    _type numb
    _units eV
    _units_detail 'electron-Volts'
    _category dft_kinetic_energy_cutoff
    _definition
; Limit of the maximum kinetic energy for charge density.
;

data_dft_kinetic_energy_cutoff_EEX
    _name '_dft_kinetic_energy_cutoff_EEX'
    _type numb
    _units eV
    _units_detail 'electron-Volts'
    _category dft_kinetic_energy_cutoff
    _definition
; Limit of the maximum kinetic energy for exact exchange (EEX) operator,
used in EEX-type calculations.
;

###############################################################################
# Energy
###############################################################################

data_dft_energy_[]
    _name '_dft_energy_[]'
    _category category_overview
    _type null
    _definition
;
  Data items in this category describe various energy terms.
;

data_dft_cell_energy
    _name '_dft_cell_energy'
    _category dft_energy
    _type numb
    _units eV
    _units_detail 'electron-Volts'
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE.
  Energy given in eV.

  S.G.: Is this supposed to be the same as 'total energy'? Will it be
  compatible with the http://www.xml-cml.org/dictionary/compchem/
  "total energy" (ID: totalEnergy) term? If so, maybe we rename this
  data item to _dft_total_energy?
;

###############################################################################
# Separate energy terms
###############################################################################

# Q: is it true that the total energy will be the sum of all
# "Separate energy terms"? (S.G.)

data_dft_kinetic_energy
_name '_dft_kinetic_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition

; The kinetic energy part of the Hamiltonian; if periodic boundary
conditions are used, should be given for one unit cell as specified by
_cell_length_* and _cell_angle_* parameters.

Q: should the nuclei kin. energy be included? Is it ever appreciable?
What about vibrational lattice modes (phonons)? (S.G.)
;

# Q: how should the following Abinit energies be represented? Vis.:
#
#     Hartree energy  =  2.27637094216573E+01
#     XC energy       = -1.81223641765291E+01 << is this the same as "correlation energy" in NWChem? S.G.
#     Ewald energy    = -3.71921214233243E+01
#     PspCore energy  =  3.22969039024445E-01
#     Loc. psp. energy= -8.28746948571284E+01
#     NL   psp  energy=  1.01185403081610E+01
# (S.G.)

data_dft_Coulomb_energy
_name '_dft_Coulomb_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition
; Should be the same as the CML (ID: coulombEnergy) term,
http://www.xml-cml.org/dictionary/compchem/#coulombEnergy.
;

data_dft_correlation_energy
_name '_dft_correlation_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition
; http://www.xml-cml.org/dictionary/compchem/#correlationEnergy (ID:
  correlationEnergy)
;

data_dft_1e_energy
_name '_dft_1e_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition
; http://www.xml-cml.org/dictionary/compchem/#e1Energy
  (ID: e1Energy)
;

data_dft_2e_energy
_name '_dft_2e_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition
; http://www.xml-cml.org/dictionary/compchem/#e2Energy
  (ID: e2Energy)
;

data_dft_nuclear_repulsion_energy
_name '_dft_nuclear_repulsion_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition
; http://www.xml-cml.org/dictionary/compchem/#nuclearRepulsionEnergy
  (ID: nuclearRepulsionEnergy)

  Q: is it not included into Coulomb energy? S.G.
;

data_dft_ewald_energy
_name '_dft_ewald_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE.
;

data_dft_fermi_energy
_name '_dft_fermi_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE.
;

data_dft_hartree_energy
_name '_dft_hartree_energy'
_category dft_energy
_type numb
_units eV
_units_detail 'electron-Volts'
_definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE.
;

###############################################################################
# Magnetic moment
###############################################################################

data_dft_cell_magn_[]
    _name '_dft_cell_magn_[]'
    _category category_overview
    _type null
    _definition
;
  Data items in this category describe the magnetic moments.
;

data_dft_cell_magn_moment
    _name '_dft_cell_magn_moment'
    _category dft_cell_magn
    _type numb
    _units \m_B
    _units_detail 'Bohr magnetons'
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_cell_magn_spin_moment
    _name '_dft_cell_magn_spin_moment'
    _category dft_cell_magn
    _type char
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_cell_magn_orbital_moment
    _name '_dft_cell_magn_orbital_moment'
    _category dft_cell_magn
    _type char
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

###############################################################################
# Convergence parameters?
###############################################################################

data_dft_cell_conv_[]
    _name '_dft_cell_conv_[]'
    _category category_overview
    _type null
    _definition
;
  Data items in this category describe convergence criteria.
;

data_dft_cell_energy_conv
    _name '_dft_cell_energy_conv'
    _category dft_cell_conv
    _type char
    _units eV
    _units_detail 'electron-Volts'
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE.
  Energy given in eV.
;

data_dft_cell_density_conv
    _name '_dft_cell_density_conv'
    _category dft_cell_conv
    _type char
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_cell_potential_conv
    _name '_dft_cell_potential_conv'
    _category dft_cell_conv
    _type char
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

###############################################################################
# Atom parameters: electron configurations, nuclear charges, etc.
###############################################################################

data_dft_atom_type_[]
    _name '_dft_atom_type_[]'
    _type null
    _category category_overview
    _definition
; Data items to describe per-atom-type properties of DFT calculations.
;

data_dft_atom_type_valence_electrons
    _name '_dft_atom_type_valence_electrons'
    _type numb
    _category dft_atom_type
    _definition
; Number of electrons contributed from an atomic type.
  (Should this be in the _atom_site_... or _atom_type_ linked loop? S.G.)
;

data_dft_atom_type_valence_configuration
    _name '_dft_atom_type_valence_configuration'
    _type char
    _category dft_atom_type
    _definition
; PLEASE GIVE A SEMI-FORMAL HUMAN-READABLE DESCRIPTION HERE.

  For example, '2s2p' for B-F or '6s6p7s5f' for actinides.
;
    loop_ _example
          _example_detail
          2s2p      'for B-F'
          6s6p7s5f  'for actinides'

data_dft_atom_type_nuclear_charge
    _name '_dft_atom_type_nuclear_charge'
    _type numb
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE SEMI-FORMAL DESCRIPTION HERE.

  This would be 76 for Os but 26.3 for a VCA calculation for the
  Slater-Pauling-curve maximum (70/30 Fe/Co).
;

data_dft_atom_type_magn_moment
    _name '_dft_atom_type_magn_moment'
    _type numb
    _units \m_B
    _units_detail 'Bohr magnetons'
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
  Magnetic moment given in \m_B.
;

data_dft_atom_type_magn_spin_moment
    _name '_dft_atom_type_magn_spin_moment'
    _type numb
    _units \m_B
    _units_detail 'Bohr magnetons'
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
  Magnetic moment given in \m_B.
;

data_dft_atom_type_magn_orbital_moment
    _name '_dft_atom_type_magn_orbital_moment'
    _type numb
    _units \m_B
    _units_detail 'Bohr magnetons'
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
  Magnetic moment given in \m_B.
;

data_dft_atom_type_occupation
    # Maybe 'occupancy'? S.G.
    _name '_dft_atom_type_occupation'
    _type numb
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_atom_type_radius
    _name '_dft_atom_type_radius'
    _type numb
    _units \%A
    _units_detail Angstroems
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE

  Radius given in \%Angstr\/oms (\%A).
;

data_dft_atom_type_coulomb_U
    _name '_dft_atom_type_coulomb_U'
    _type numb
    _units eV
    _units_detail 'electron-Volts'
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
  Energy given in eV.
;

data_dft_atom_type_coulomb_J
    _name '_dft_atom_type_coulomb_J'
    _type numb
    _units eV
    _units_detail 'electron-Volts'
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
  Energy given in eV.
;

data_dft_atom_relax_force_conv
    _name '_dft_atom_relax_force_conv'
    _type char
    _units eV/\%A
    _units_detail 'electron-Volts per Angstroem'
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE

  In eV/\%A.
;

data_dft_atom_relax_energy_conv
    _name '_dft_atom_relax_energy_conv'
    _type char
    _units eV
    _units_detail 'electron-Volts'
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE

  In eV.
;

data_dft_atom_type_double_count
    # Qu'est-ce que c'est? Why 'double count'?
    _name '_dft_atom_type_double_count'
    _type numb
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_atom_type_DMFT_solver
    _name '_dft_atom_type_DMFT_solver'
    _type char
    _category dft_atom_type
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

###############################################################################
# Data items required to model metal alloys:
###############################################################################

data_dft_alloy_[]
    _name '_dft_alloy_[]'
    _type null
    _category category_overview
    _definition
; Data items to describe modelling of metal alloys.
;

data_dft_alloy_method
    _name '_dft_alloy_method'
    _type char
    _category dft_alloy
    loop_ _enumeration
          _enumeration_detail
        VCA                    'virtual crystal approximation'
        CPA                    'coherent potential approximation'
        SQS                    'special quasirandom structures'
        'real space recursion' 'describe the corresponding method here'
        other                  'alloy method not one of the mentioned above'
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_alloy_method_other_name
    _name '_dft_alloy_method_other_name'
    _type char
    _category dft_alloy
    _definition
; Custom name of the alloy method if _dft_alloy_method data item value
  is given as 'other'.
;

data_dft_alloy_supercell
    _name '_dft_alloy_supercell'
    _type char
    _category dft_alloy
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE

  For such alloy methods that require supercells.
;

###############################################################################
# Other calculated material properties.
###############################################################################

data_dft_calc_property_[]
    _name '_dft_calc_property_[]'
    _category category_overview
    _type null
    _definition
; Data items to describe other calculated material properties.
;

data_dft_lattice_energy
    _name '_dft_lattice_energy'
    _category dft_calc_property
    _type numb
    _units kJ/mol
    _units_detail 'kilojoules per mole'
    _definition
; Energy of formation of the crystal from infinitely-separated ions,
  molecules, or atoms.
;

data_dft_bulk_modulus
    _name '_dft_bulk_modulus'
    _category dft_calc_property
    _type numb
    _units GPa
    _units_detail gigapascals
    _definition
; Ratio of the infinitesimal pressure increase to the resulting relative
  decrease of the volume.
;

data_dft_stiffness_tensor_
    loop_ _name
        '_dft_stiffness_tensor_11'
        '_dft_stiffness_tensor_12'
        '_dft_stiffness_tensor_13'
        '_dft_stiffness_tensor_14'
        '_dft_stiffness_tensor_15'
        '_dft_stiffness_tensor_16'
        '_dft_stiffness_tensor_22'
        '_dft_stiffness_tensor_23'
        '_dft_stiffness_tensor_24'
        '_dft_stiffness_tensor_25'
        '_dft_stiffness_tensor_26'
        '_dft_stiffness_tensor_33'
        '_dft_stiffness_tensor_34'
        '_dft_stiffness_tensor_35'
        '_dft_stiffness_tensor_36'
        '_dft_stiffness_tensor_44'
        '_dft_stiffness_tensor_45'
        '_dft_stiffness_tensor_46'
        '_dft_stiffness_tensor_55'
        '_dft_stiffness_tensor_56'
        '_dft_stiffness_tensor_66'
    _category dft_calc_property
    _type numb
    _units GPa
    _units_detail gigapascals
    _enumeration_default 0
    _definition
; Stiffness tensor matrix.
;

data_dft_band_gap
    _name '_dft_band_gap'
    _category dft_calc_property
    _type numb
    _units eV
    _units_detail electronvolts
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;

data_dft_dielectric_constant
    _name '_dft_dielectric_constant'
    _category dft_calc_property
    _type numb
    _definition
; PLEASE ADD A HUMAN-READABLE DESCRIPTION HERE
;