Powder dictionary (pdCIF) version 1.0.1
_pd_block_id
Name:'_pd_block_id'
Definition:
Used to assign a unique character string to a block.
Note that this code is not intended to be parsed; the
concatenation of several strings is used in order to
generate a string that can reasonably be expected to
be unique.
This code is assigned by the originator of the data set and
is used for references between different CIF blocks.
The ID will normally be created when the block is first
created. It is possible to loop more than one ID for a
block: if changes or additions are made to the
block later, a new ID may be assigned, but the original name
should be retained.
The format for the ID code is:
<date-time>|<block_name>|<creator_name>|<instr_name>
<date-time> is the date and time the CIF was created
or modified.
<block_name> is an arbitrary name assigned by the
originator of the data set. It will
usually match the name of the phase
and possibly the name of the current CIF
data block (i.e. the string xxxx in a
data_xxxx identifier). It may be a sample name.
<creator_name> is the name of the person who measured the
diffractogram, or prepared or modified the CIF.
<instr_name> is a unique name (as far as possible) for
the data-collection instrument, preferably
containing the instrument serial number for
commercial instruments. It is also possible to
use the Internet name or address for the
instrument computer as a unique name.
As blocks are created in a CIF, the original sample identifier
(i.e. <block_name>) should be retained, but the <creator_name>
may be changed and the <date-time> will always change.
The <date-time> will usually match either the
_pd_meas_datetime_initiated or the _pd_proc_info_datetime
entry.
Within each section of the code, the following characters
may be used:
A-Z a-z 0-9 # & * . : , - _ + / ( ) \ [ ]
The sections are separated with vertical rules '|' which are
not allowed within the sections. Blank spaces may also
not be used. Capitalization may be used within the ID code
but should not be considered significant - searches for
data-set ID names should be case-insensitive.
Date-time entries are in the standard CIF format
'yyyy-mm-ddThh:mm:ss+zz' Use of seconds and a time zone
is optional, but use of hours and minutes is strongly
encouraged as this will help ensure that the ID code is unique.
An archive site that wishes to make CIFs available via
the web may substitute the URL for the file containing the
appropriate block for the final two sections of the ID
(<creator_name> and <instr_name>). Note that this should
not be done unless the archive site is prepared to keep the
file available online indefinitely.
Examples:| 1991-15-09T16:54|Si-std|B.Toby|D500#1234-987 |
| 1991-15-09T16:54|SEPD7234|B.Toby|SEPD.IPNS.ANL.GOV |
May appear in list
Type: char
Category: pd_block