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Re: Round 3 of CIF core revision



Dear David,

It is neither apathy nor approval. I am still departmental chairperson
and term has just started and I simply do not have time at the moment to
give it the attention it deserves. Note that I have agreed with Bill
Clegg and other Editors of Acta that he will supply me with a list of
CIF items that it would be desirable to include in the next release of
SHELX for the purpose of submitting papers to Acta, it is therefore
important that any new items that will be required for this get into his
list. 

Best wishes, George

"I. David Brown" wrote:
> 
> Dear colleagues,
> 
>      The deadline for comments on the previous set of proposed
> changes to the CIF core dictionary (Cell and Chemical categories)
> has come and gone and I have received one response which pointed
> out a few typographical errors.  These have been corrected.  The
> lack of replies from the rest of you is either a sign of apathy
> or approval.  In the absence of positive evidence of apathy (such
> as an email saying you are too bored to check through the
> proposals) I interpret silence as approval and declare the Cell
> and Chemical items approved.
> 
>      In this email I list below proposals in the Citation, Database
> and Diffrn categories.  Note that some of these items have
> already been approved but they are included here for
> completeness.  If there are problems with these items, we can
> reopen the discussion.
> 
> PLEASE RESPOND BEFORE NOVEMBER 11.
> 
> Again, silence means approval but your positive comments are
> welcome as evidence that you are still alive and are receiving
> (and reading) your email.
> 
>                     Best wishes
> 
>                          David
> 
> Proposal below - keep on scrolling
> *****************************************************
> Dr.I.David Brown,  Professor Emeritus
> Brockhouse Institute for Materials Research,
> McMaster University, Hamilton, Ontario, Canada
> Tel: 1-(905)-525-9140 ext 24710
> Fax: 1-(905)-521-2773
> idbrown@mcmaster.ca
> *****************************************************
> 
> ##############################################
> #
> #  Items included in this round
> #
> ##############################################
> #
> #     CITATION
> #        _citation_database_id_CSD
> #     DATABASE
> #        _database_code_depnum_ccdc_fiz
> #        _database_code_depnum_ccdc_journal
> #        _database_code_depnum_ccdc_archive
> #        _database_CSD_history
> #     DIFFRN
> #        _diffrn_ambient_pressure_gt
> #        _diffrn_ambient_pressure_lt
> #        _diffrn_ambient_temperature_gt
> #        _diffrn_ambient_temperature_lt
> #     DIFFRN_STANDARDS
> #        _diffrn_standards_decay_%_lt
> #     DIFFRN_REFLNS
> #        _diffrn_reflns_measured_faction_resolution_full
> #        _diffrn_reflns_measured_faction_resolution_max
> #        _diffrn_reflns_resolution_full
> #        _diffrn_reflns_resolution_max
> 
> ###################################################
> #
> #   CITATION category
> #
> ###################################################
> 
> data_citation_database_id_CSD
>     _name                     '_citation_database_id_CSD'
>     _category                  citation
>     _type                      char
>     _list                      yes
>     _list_reference           '_citation_id'
>     _example                   LEKKUH
>     _definition
> ;           Identifier ('refcode') of the database record in the Cambridge
>             Structural Database containing details of the cited structure.
> ;
> # COMMENT: Submitted by Brian McMahon
> # STATUS: Approved 2001-12-03
> 
> ####################################################
> #
> #   DATABASE Category
> #
> ####################################################
> 
> data_database_code_depnum_ccdc_fiz
>     _name                     '_database_code_depnum_ccdc_fiz'
>     _category                  database
>     _type                      char
>     _definition
> ;              Deposition numbers assigned by the Fachinformatsions Zentrum
>                Karlsruhe (FIZ) to files containing structural information
>                archived by the Cambridge Crystallographic Centre (CCDC)
> ;
> # COMMENT: For use in the archives of CCDC.  Submitted by CCDC
> # STATUS: approved 2002-02-28
> 
> data_database_code_depnum_ccdc_journal
>     _name                     '_database_code_depnum_ccdc_journal'
>     _category                  database
>     _type                      char
>     _definition
> ;              Deposition numbers assigned by various journal to files
>                containing structural information archived by the Cambridge
>                Crystallographic Data Centre (CCDC)
> ;
> # COMMENT: For use in the archives of CCDC.  Submitted by CCDC
> # STATUS: approved 2002-02-28
> 
> data_database_code_depnum_ccdc_archive
>     _name                     '_database_code_depnum_ccdc_archive'
>     _category                  database
>     _type                      char
>     _definition
> ;              Deposition numbers assigned by  the Cambridge Crystallographic
>                Data Centre (CCDC) to files containing structural information
>                archived by the CCDC.
> ;
> 
> # COMMENT: For use in the archives of CCDC.  Submitted by CCDC
> # STATUS: approved 2002-02-28
> 
> data _database_CSD_history
>     _name                     '_database_CSD_history'
>     _category                  database
>     _type                      char
>     _list                      yes
>     _list_reference            ?
>     _example                   ?
>     _definition
> ;              A history of changes made by Cambridge Crystallographic Data
>                Centre and incorporated into the Cambridge Structural Database
>                (CSD).
> ;
> # COMMENT: Requested by the CCDC
> # STATUS: Open for discussion
> 
> ###########################################
> #
> #   DIFFRN category
> #
> ###########################################
> 
> data_diffrn_ambient_pressure_*
>     loop_    _name
>                               '_diffrn_ambient_pressure_gt'
>                               '_diffrn_ambient_pressure_lt'
>     _category                  diffrn
>     _type                      numb
>     _type_conditions           esd
>     _enumeration_range         0.0:
>     _units                     kPa
>     _units_detail             'kilopascals'
>     _definition
> ;              The mean pressure in kilopascals above which (_*_gt) or below
>                which (_*_lt) the intensities were measured.
> ;
> # COMMENT; Provides for a pressure range to be indicated.
> # STATUS: Open for discussion
> 
> data_diffrn_ambient_temperature_*
>     loop_       _name
>                               '_diffrn_ambient_temperature_gt'
>                               '_diffrn_ambient_temperature_lt'
>     _category                  diffrn
>     _type                      numb
>     _type_conditions           esd
>     _enumeration_range         0.0:
>     _units                     K
>     _units_detail             'kelvins'
>     _definition
> ;             The mean temperature in kelvins above which (_*_gt) or below
>               which (_*_lt) the intensities were measured.
> ;
> # COMMENT: Provides for a range of temperatures to be specified.
> # STATUS: Open for discussion
> 
> ################################################
> #
> #   DIFFRN_SOURCE
> #
> ################################################
> 
> data_diffrn_source_take-off_angle
>     _name                     '_diffrn_source_take-off_angle'
>     _category                  diffrn_source
>     _type                      numb
>     _enumeration_range         0:90
>     _units                     degrees
>     _example                   ?
>     _definition
> ;              The angle between the surface of the target and the x-ray beam
>                for beams generated by traditional x-ray tubes.
> ;
> # COMMENT: Suggested by the powder DMG.
> # STATUS: Open for discussion
> 
> ######################################
> #
> #   DIFFRN_STANDARDS category
> #
> ######################################
> 
> data_diffrn_standards_decay_%
>     _name                      '_diffrn_standards_decay_%_lt'
>     _category                   diffrn_standards
>     _type                       numb
>     _enumeration_range          :100
>     _definition
> ;              An upper limit on the percentage decrease in the mean
>                intensity of the set of standard reflections measured at the
>                start of the measurement of the diffraction pattern and at the
>                end. This value is used when the decay is too small to be
>                detected.
> ;
> # COMMENT: Many experiments show no detectable decay and there is no provision
> # of this at the moment other than to enter 0.0.
> # STATUS: Open for discussion
> 
> #################################################
> #
> #  DIFFRN_REFLNS
> #
> #################################################
> 
> data_diffrn_reflns_measured_faction_resolution_full
>     _name                '_diffrn_reflns_measured_faction_resolution_full'
>     _category                   diffrn_reflns
>      _list                      yes
>      _type                      numb
>      _enumeration_range         0:1.0
>      _related_item             '_diffrn_measured_fraction_theta_full'
>      _related_function          replace
>      _definition
> ;         Fraction of unique (symmetry-independent) reflections measured
>           out to the resolution given in _diffrn_reflns_resolution_full.
>           This number should be very close to 1.0, since it represents the
>           fraction of reflections measured in the part of the diffraction
>           pattern that is essentially complete.
> ;
> # COMMENT: Replacement for _diffrn_measured_fraction_theta_full, moved to a
> # more appropriate category and defined in terms of resolution rather than
> # angle which depends on the radiation used.
> # STATUS: Open for discussion
> 
> data__diffrn_reflns_measured_faction_resolution_max
>     _name                '_diffrn_reflns_measured_faction_resolution_max'
>     _category                   diffrn_reflns
>      _list                      yes
>      _type                      numb
>      _enumeration_range         0:1.0
>     _related_item              '_diffrn_measured_fraction_theta_max'
>     _related_function           replace
>      _definition
> ;         Fraction of unique (symmetry-independent) reflections measured
>           out to the resolution given in _diffrn_reflns_resolution_max.
> ;
> # COMMENT: Replacement for _diffrn_measured_fraction_theta_max, moved to a
> # more appropriate category and defined in terms of resolution rather than
> # angle which depends on the radiation used.
> # STATUS: Open for discussion
> 
> data_diffrn_reflns_resolution_full
>     _name                      '_diffrn_reflns_resolution_full'
>     _category                   diffrn_reflns
>     _type                       numb
>     _enumeration_range          0.0:
>     _units                      A^-1^
>     _units_detail              'reciprocal angstroms'
>     _related_item              '_diffrn_reflns_theta_full'
>     _related_function           replace
>     _definition
> ;              The resolution in reciprocal angstroms at which the measured
>                reflection count is close to complete. The fraction of unique
>                reflections measured out to this resolution is given by
>                _diffrn_reflns_measured_faction_resolution_full
> ;
> # COMMENT: Replacement for _diffrn_reflns_theta_full expressed in terms of
> # resolution rather than an angle that depends on the radiation used.
> # STATUS: Open for discussion
> 
> data_diffrn_reflns_resolution_max
>     _name                      '_diffrn_reflns_resolution_max'
>     _category                   diffrn_reflns
>     _type                       numb
>     _enumeration_range          0.0:
>     _units                      A^-1^
>     _units_detail              'reciprocal angstroms'
>     _related_item              '_diffrn_reflns_theta_max'
>     _related_function           replace
>     _definition
> ;              Maximum resolution of the measured diffraction pattern.
> ;
> # COMMENT: Replacement for _diffrn_reflns_theta_max expressed in terms of
> # resolution rather than an angle that depends on the radiation used.
> # STATUS: Open for discussion

-- 
Prof. George M. Sheldrick FRS
Dept. Structural Chemistry, 
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-3021 or -3068
Fax. +49-551-39-2582

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