/
cif_pd.dic
2620 lines (2389 loc) · 115 KB
/
cif_pd.dic
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
##############################################################################
# #
# Powder CIF Dictionary #
# --------------------- #
# #
# CIF data definitions specifically for powder diffraction applications. #
# These are in addition to those defined in the Core CIF Dictionary 1996. #
# #
# The DDL commands used in this dictionary are defined in "ddl_core.dic". #
# #
##############################################################################
data_on_this_dictionary
_dictionary_name cif_pd.dic
_dictionary_version 1.0.2-dev-1
_dictionary_update 2021-03-23
_dictionary_history
;
1991-08-28 Initial definitions B.H. Toby
1991-09-15 More definitions added B.H. Toby
1991-09-21 Still More definitions B.H. Toby
1991-09-24 Some updates from down under |:-) S.R. Hall
1991-10-07 Unable to leave well enough alone... B.H. Toby
1991-10-10 Some additional fine tuning (-:| S.R. Hall
1991-10-14 Minor touchups B.H. Toby
1991-12-08 Back to Work... B.H. Toby
1992-01-07 Add _pd_refln_ to allow for mixtures B.H. Toby
1992-02-07 Some redefinitions S.R. Hall
1992-02-25 Defining standards is a fiddly business S.R. Hall
1992-03-18 And still more... B.H. Toby
1992-05-22 Minor cleanup B.H. Toby
1992-05-23 Quasar says that all is OK now... S.R. Hall
1992-05-30 Changes from comments @ APD-II B.H. Toby
1992-08-18 Add calculated pattern definitions B.H. Toby
1992-08-28 Change 'powder' to 'pw' B.H. Toby
1992-08-31 Major overhaul of some definitions B.H. Toby
1992-09-01 Small adjustments S.R. Hall
1992-10-01 Change 'pw' to 'pd' B.H. Toby
1993-04-16 Change usage for multiple detectors B.H. Toby
1993-04-19 Change *_raw_ to *_meas_; *_sample_ to *_samp_
Install new DDL commands; new *_phase_ group S.R. Hall
1993-05-22 Fix _pd_calib_ defs; Minor editing B.H. Toby
1993-05-31 Still more minor editing B.H. Toby
1993-06-02 Application of new DDL commands S.R. Hall
1993-08-13 Last stop before Beijing, more descriptive entries &
more descriptive text added; support for film data. B.H. Toby
1993-10-27 My two cents worth I.D. Brown
1994-01-23 Change two to 2.5; sample to specimen. B.H. Toby
1994-03-13 Change date/time usage
Be more careful about pd_proc usage: separate data
& processing conditions B.H. Toby
1994-04-11 Start work on categories: move all diffractogram
items (that might ever be in a single loop) into
pd_data. B.H. Toby
1994-05-11 Start revisions based on I.D. Brown's comments B.H. Toby
1994-06-25 Complete revisions prior to ACA B.H. Toby
1994-10-27 Working draft B.H. Toby
1995-10-23 Implemented _units and _units_detail B. McMahon
1995-10-24 Transferred _pd_instr_radiation_probe to the core
as _diffrn_radiation_probe B. McMahon
1997-01-30 Final cleanup: removed _nm units; add units to
definitions; add _pd_block_diffractogram_id;
change _pd_meas_distance_value to _pd_meas_position;
remove _pd_proc_wavelength_nm, _pd_proc_d_spacing_nm;
_pd_proc_recip_len_Q_nm, and _pd_peak_d_spacing_nm
B.H. Toby
1997-01-31 Changed dictionary_definition to category_overview;
removed data_include_dependent_dictionaries and global_
blocks; some typos fixed B. McMahon
1997-02-12 Some typos fixed B. McMahon
1997-02-18 References to e.s.d. changed to s.u. etc.
Notation for Bragg and expected R factors changed to
R~B~ and R~exp~
B. McMahon
1997-03-10 Category of _pd_refln_ things changed to 'refln'; category of`
_pd_proc_number_of_points changed to 'pd_proc_info'; some
rewording of descriptions involving s.u.s according to BT;
changed 'samp' to 'spec' in many datanames relating distances
to specimen; changed style of these and similar to *_src/spec
etc; _pd_calc_method no longer has '_list yes'; _list_uniqueness
deleted from _pd_refln_peak_id; use of '.' instead of '?'
recommended in a couple of places; addition of example to
_pd_calib_conversion_eqn; '_pd_proc_intensity_calc_bkg' and
'_fix_bkg' changed to '_pd_proc_intensity_bkg_calc' and '_fix'
B. McMahon
1997-03-12 Category of _pd_calib_ things changed to 'pd_calib';
_pd_calib_conversion_eqn and *_special_details renamed as
_pd_calibration_* and assigned to category 'pd_calibration'
Alphabetised entries within category.
B. McMahon
1997-03-17 Copyediting changes to punctuation and spelling. B. McMahon
1997-10-29 Changed _pd_calib_std_external_id to
_pd_calib_std_external_block_id. Moved _pd_proc_2theta_range_ to
category pd_proc_info (because not looped with other pd_data
items).
B. McMahon
1997-10-29 Release version 1.0 B. McMahon
2005-01-07 NJA: minor corrections to hyphenation, spelling and punctuation
pd_data_[pd]: Example 3, second loop _pd_calc_2theta_scan
changed to _pd_proc_2theta_corrected
_pd_instr_cons_illum_len: definition rephrased
_pd_phase_[pd]: first sentence of definition rephrased
_pd_proc_ls_background_function: second paragraph of
definition rephrased
2017-06-30 Maintenance update:
Moved all unlooped instances of _related_function to
a loop structure as required by the ddl.dic. A. Vaitkus
2021-03-23 Maintenance update:
Homogenised the values of the _units and _units_detail
data items.
;
#......................... Block/Data set names
data_pd_block_[pd]
_name '_pd_block_[pd]'
_category category_overview
_type null
_definition
; _pd_block_id is used to assign a unique ID code to a data block.
This code is then used for references between different blocks
(see _pd_block_diffractogram_id, _pd_calib_std_external_block_id
and _pd_phase_block_id).
Note that a data block may contain only a single diffraction
data set or information about a single crystalline phase.
However, a single diffraction measurement may yield structural
information on more than one phase, or a single structure
determination may use more than one data set. Alternatively,
results from a single data set, such as calibration parameters
from measurements of a standard, may be used for many subsequent
analyses. Through use of the ID code, a reference made between
data sets may be preserved when the file is exported from the
laboratory from which the CIF originated.
The ID code assigned to each data block should be unique with
respect to an ID code assigned for any other data block in the
world. The naming scheme chosen for the block-ID format is
designed to ensure uniqueness.
It is the responsibility of a data archive site or local
laboratory to create a catalogue of block ID's if that site
wishes to resolve these references.
;
data_pd_block_diffractogram_id
_name '_pd_block_diffractogram_id'
_category pd_proc
_type char
_list yes
_definition
; A block ID code (see _pd_block_id) that identifies
diffraction data contained in a data block other
than the current block. This will occur most frequently
when more than one set of diffraction data
is used for a structure determination. The data
block containing the diffraction data will contain
a _pd_block_id code matching the code in
_pd_block_diffractogram_id.
;
data_pd_block_id
_name '_pd_block_id'
_category pd_block
_type char
_list both
loop_ _example
1991-15-09T16:54|Si-std|B.Toby|D500#1234-987
1991-15-09T16:54|SEPD7234|B.Toby|SEPD.IPNS.ANL.GOV
_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.
;
#......................... Measured Diffractogram Information
data_pd_meas_[pd]
_name '_pd_meas_[pd]'
_category category_overview
_type null
loop_
_example
_example_detail
#----------------------------------------------------------------------------
;
_pd_meas_info_author_name 'Cranswick, Lachlan'
_pd_meas_info_author_email lachlan@dmp.csiro.au
_pd_meas_info_author_address ?
_pd_meas_datetime_initiated 1992-03-23T17:20
_pd_meas_scan_method step
_pd_meas_2theta_range_min 6.0
_pd_meas_2theta_range_max 164.0
_pd_meas_2theta_range_inc 0.025
_pd_meas_step_count_time 2.0
;
;
Example 1.
;
#----------------------------------------------------------------------------
_definition
; This section contains the measured diffractogram and information
about the conditions used for the measurement of the diffraction
data set, prior to processing and application of correction
terms. While additional information may be added to the CIF
as data are processed and transported between laboratories
(possibly with the addition of a new _pd_block_id entry), the
information in this section of the CIF will rarely be changed
once data collection is complete.
Where possible, measurements in this section should have no
post-collection processing applied (normalizations, corrections,
smoothing, zero-offset corrections etc.). Such corrected
measurements should be recorded in the _pd_proc_ section.
Data sets that are measured as counts, where a standard
uncertainty can be considered equivalent to the standard
deviation and where the standard deviation can be estimated
as the square root of the number of counts recorded, should
use the _pd_meas_counts_ fields. All other intensity values
should be recorded using _pd_meas_intensity_.
;
data_pd_meas_2theta_fixed
_name '_pd_meas_2theta_fixed'
_category pd_meas_method
_type numb
_type_conditions esd
_enumeration_range -180.0:360.0
_definition
; The 2\q diffraction angle in degrees for measurements
in a white-beam fixed-angle experiment. For measurements
where 2\q is scanned, see _pd_meas_2theta_scan or
_pd_meas_2theta_range_.
;
data_pd_meas_2theta_range_
loop_ _name '_pd_meas_2theta_range_min'
'_pd_meas_2theta_range_max'
'_pd_meas_2theta_range_inc'
_category pd_meas_method
_type numb
_enumeration_range -180.0:360.0
_definition
; The range of 2\q diffraction angles in degrees for the
measurement of intensities. These may be used in place of the
_pd_meas_2theta_scan values for data sets measured with a
constant step size.
;
data_pd_meas_2theta_scan
_name '_pd_meas_2theta_scan'
_category pd_data
_type numb
_type_conditions esd
_list yes
_enumeration_range -180.0:360.0
_definition
; 2\q diffraction angle (in degrees) for intensity
points measured in a scanning method. The scan method used
(e.g. continuous or step scan) should be specified in
the item _pd_meas_scan_method. For fixed 2\q (white-beam)
experiments, use _pd_meas_2theta_fixed. In the case of
continuous-scan data sets, the 2\q value should be the
value at the midpoint of the counting period. Associated
with each _pd_meas_2theta_scan value will be
_pd_meas_counts_ items. The 2\q values should
not be corrected for nonlinearity,
zero offset etc. Corrected values may be specified
using _pd_proc_2theta_corrected.
Note that for data sets collected with constant step size,
_pd_meas_2theta_range_ (*_min, *_max and *_inc) may be
used instead of _pd_meas_2theta_scan.
;
data_pd_meas_angle_
loop_ _name '_pd_meas_angle_chi'
'_pd_meas_angle_omega'
'_pd_meas_angle_phi'
'_pd_meas_angle_2theta'
_category pd_data
_type numb
_list both
_enumeration_range -180.0:360.0
_definition
; The diffractometer angles in degrees for an instrument with a
Euler circle. The definitions for these angles follow the
convention of International Tables for X-ray Crystallography
(1974), Vol. IV, p. 276.
;
data_pd_meas_counts_
loop_ _name '_pd_meas_counts_total'
'_pd_meas_counts_background'
'_pd_meas_counts_container'
'_pd_meas_counts_monitor'
_category pd_data
_type numb
_list yes
_enumeration_range 0:
_definition
; Counts measured at the measurement point as a function of
angle, time, channel or some other variable (see
_pd_meas_2theta_ etc.).
The defined fields are:
_pd_meas_counts_total, scattering from the specimen
(with background, specimen mounting or container
scattering included);
_pd_meas_counts_background, scattering measured
without a specimen, specimen mounting etc., often
referred to as the instrument background;
_pd_meas_counts_container, the specimen container or
mounting without a specimen, includes background;
_pd_meas_counts_monitor, counts measured by an
incident-beam monitor to calibrate the flux on the
specimen.
Corrections for background, detector dead time etc.
should not have been made to these values. Instead use
_pd_proc_intensity_ for corrected diffractograms.
Note that counts-per-second values should be converted to
total counts. If the counting time varies for different
points, it may be included in the loop using
_pd_meas_step_count_time.
Standard uncertainties should not be quoted for these values.
If the standard uncertainties differ from the square root of
the number of counts, _pd_meas_intensity_ should be used.
;
data_pd_meas_datetime_initiated
_name '_pd_meas_datetime_initiated'
_category pd_meas_method
_type char
_example 1990-07-13T14:40
_definition
; The date and time of the data-set measurement. Entries follow
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. Where possible, give the
time when the measurement was started rather than when
it was completed.
;
data_pd_meas_detector_id
_name '_pd_meas_detector_id'
_category pd_data
_type char
_list yes
_list_link_parent '_pd_calib_detector_id'
_definition
; A code or number which identifies the measuring detector or
channel number in a position-sensitive, energy-dispersive
or other multiple-detector instrument.
Calibration information, such as angle offsets or
a calibration function to convert channel numbers
to Q, energy, wavelength, angle etc. should
be described with _pd_calib_ values. If
_pd_calibration_conversion_eqn is used, the detector ID's
should be the number to be used in the equation.
;
data_pd_meas_info_author_address
_name '_pd_meas_info_author_address'
_category pd_meas_info
_type char
_list both
_list_reference '_pd_meas_info_author_name'
_definition
; The address of the person who measured the data set. If there
is more than one person, this will be looped with
_pd_meas_info_author_name.
;
data_pd_meas_info_author_email
_name '_pd_meas_info_author_email'
_category pd_meas_info
_type char
_list both
_list_reference '_pd_meas_info_author_name'
_definition
; The e-mail address of the person who measured the data set. If
there is more than one person, this will be looped with
_pd_meas_info_author_name.
;
data_pd_meas_info_author_fax
_name '_pd_meas_info_author_fax'
_category pd_meas_info
_type char
_list both
_list_reference '_pd_meas_info_author_name'
_definition
; The fax number of the person who measured the data set. If
there is more than one person, this will be looped with
_pd_meas_info_author_name. The recommended style is
the international dialing prefix, followed by the area code in
parentheses, followed by the local number with no spaces.
;
data_pd_meas_info_author_name
_name '_pd_meas_info_author_name'
_category pd_meas_info
_type char
_list both
_definition
; The name of the person who measured the data set. The family
name(s), followed by a comma and including any dynastic
components, precedes the first name(s) or initial(s).
For more than one person use a loop to specify multiple values.
;
data_pd_meas_info_author_phone
_name '_pd_meas_info_author_phone'
_category pd_meas_info
_type char
_list both
_list_reference '_pd_meas_info_author_name'
_definition
; The telephone number of the person who measured the data set.
If there is more than one person, this will be looped with
_pd_meas_info_author_name. The recommended style is
the international dialing prefix, followed by the area code in
parentheses, followed by the local number with no spaces.
;
data_pd_meas_intensity_
loop_ _name '_pd_meas_intensity_total'
'_pd_meas_intensity_background'
'_pd_meas_intensity_container'
'_pd_meas_intensity_monitor'
_category pd_data
_type numb
_type_conditions esd
_list yes
_definition
; Intensity measurements at the measurement point (see
the definition of _pd_meas_2theta_).
The defined fields are:
_pd_meas_intensity_total, scattering from the specimen
(with background, specimen mounting or container
scattering included);
_pd_meas_intensity_background, scattering measured
without a specimen, specimen mounting etc., often
referred to as the instrument background;
_pd_meas_intensity_container, the specimen container or
mounting without a specimen, includes background;
_pd_meas_intensity_monitor, intensity measured by an
incident-beam monitor to calibrate the flux on the specimen.
Use these entries for measurements where intensity
values are not counts (use _pd_meas_counts_ for event-counting
measurements where the standard uncertainty is
estimated as the square root of the number of counts).
Corrections for background, detector dead time etc.,
should not have been made to these values. Instead use
_pd_proc_intensity_ for corrected diffractograms.
_pd_meas_units_of_intensity should be used to specify
the units of the intensity measurements.
;
data_pd_meas_number_of_points
_name '_pd_meas_number_of_points'
_category pd_meas_method
_type numb
_enumeration_range 1:
_definition
; The total number of points in the measured
diffractogram.
;
data_pd_meas_position
_name '_pd_meas_position'
_category pd_data
_type numb
_type_conditions esd
_list yes
_units mm
_units_detail millimetre
_definition
; A linear distance in millimetres corresponding to the
location where an intensity measurement is made.
Used for detectors where a distance measurement is made
as a direct observable, such as from a microdensitometer
trace from film or a strip chart recorder. This is an
alternative to _pd_meas_2theta_scan, which should only be
used for instruments that record intensities directly
against 2\q. For instruments where the position scale
is nonlinear, the data item _pd_meas_detector_id should
be used to record positions.
Calibration information, such as angle offsets or a
function to convert this distance to a 2\q angle
or d-space, should be supplied with the _pd_calib_ values.
Do not confuse this with the instrument geometry
descriptions given by _pd_instr_dist_.
;
data_pd_meas_rocking_angle
_name '_pd_meas_rocking_angle'
_category pd_data
_type numb
_list both
_units deg
_units_detail 'degree of arc'
_enumeration_range 0:360.0
_definition
; The angular range in degrees through which a sample is rotated
or oscillated during a measurement step
(see _pd_meas_rocking_axis).
;
data_pd_meas_rocking_axis
_name '_pd_meas_rocking_axis'
_category pd_meas_method
_type char
loop_ _enumeration chi
omega
phi
_definition
; Description of the axis (or axes) used to rotate or rock the
specimen for better randomization of crystallites
(see _pd_meas_rocking_angle).
;
data_pd_meas_scan_method
_name '_pd_meas_scan_method'
_category pd_meas_method
_type char
loop_ _enumeration
_enumeration_detail step 'step scan'
cont 'continuous scan'
tof 'time of flight'
disp 'energy dispersive'
fixed 'stationary detector'
_definition
; Code identifying the method for scanning reciprocal space.
The designation `fixed' should be used for measurements where
film, a stationary position-sensitive or area detector
or other non-moving detection mechanism is used to
measure diffraction intensities.
;
data_pd_meas_special_details
_name '_pd_meas_special_details'
_category pd_meas_method
_type char
_definition
; Special details of the diffraction measurement process.
Include information about source instability, degradation etc.
However, this item should not be used to record information
that can be specified in other _pd_meas_ entries.
;
data_pd_meas_step_count_time
_name '_pd_meas_step_count_time'
_category pd_data
_type numb
_type_conditions esd
_list both
_units s
_units_detail second
_enumeration_range 0.0:
_definition
; The count time in seconds for each intensity measurement.
If this value varies for different intensity measurements,
then this item will be placed in the loop with the
diffraction measurements. If a single fixed value is used,
it may be recorded outside the loop.
;
data_pd_meas_time_of_flight
_name '_pd_meas_time_of_flight'
_category pd_data
_type numb
_type_conditions esd
_list yes
_units \ms
_units_detail microsecond
_enumeration_range 0:
_definition
; Measured time in microseconds for time-of-flight neutron
measurements. Note that the flight distance may be
specified using _pd_instr_dist_ values.
;
data_pd_meas_units_of_intensity
_name '_pd_meas_units_of_intensity'
_category pd_meas_method
_type char
loop_ _example 'estimated from strip chart'
'arbitrary, from film density'
'counts, with automatic dead-time correction applied'
_definition
; Units for intensity measurements when _pd_meas_intensity_
is used. Note that use of 'counts' or 'counts per second'
here is strongly discouraged: convert the intensity
measurements to counts and use _pd_meas_counts_ and
_pd_meas_step_count_time instead of _pd_meas_intensity_.
;
#........................... Calibration Information
data_pd_calib_[pd]
_name '_pd_calib_[pd]'
_category category_overview
_type null
loop_
_example
_example_detail
#----------------------------------------------------------------------------
;
_pd_calib_std_external_block_id
QuartzPlate|D500#1234-987|B.Toby|91-15-09|14:02
_pd_calib_std_external_name
'Arkansas Stone quartz plate'
;
;
Example 1.
;
;
_pd_calibration_conversion_eqn
; 2\q~actual~ = 2\q~setting~ + arctan(
cos(P~1~)/{1/[P~0~ (CC - CH~0~ - P~2~ CC^2^)] - sin(P~1~)})
;
;
;
Example 2 -
2\q~actual~ = 2\q~setting~ + arctan( cos(P~1~) / {1/[P~0~
(CC - CH~0~ - P~2~ CC^2^)] - sin(P~1~)} ).
This allows for the calibration of 2\q for a linear
position-sensitive detector (PSD) where the PSD has been
set so that the 'centre channel' (CH~0~) is located at
2\q~setting~ as a function of the channel number (CC). In
addition to CH~0~, variables P~0~, P~1~ and P~2~ are
calibration constants, where P~0~ is the width of a PSD
channel in degrees, P~1~ is the angle of the PSD with respect
to the perpendicular and P~2~ is a quadratic term for
nonlinearities in the detector.
;
#----------------------------------------------------------------------------
_definition
; This section defines the parameters used for the calibration
of the instrument that are used directly or indirectly in the
interpretation of this data set. The information in this
section of the CIF should generally be written when the
intensities are first measured, but from then on should remain
unchanged. Loops may be used for calibration information that
differs by detector channel. The _pd_calibration_ items,
however, are never looped.
;
data_pd_calib_2theta_
loop_ _name '_pd_calib_2theta_offset'
'_pd_calib_2theta_off_point'
'_pd_calib_2theta_off_min'
'_pd_calib_2theta_off_max'
_category pd_calib
_type numb
_list both
_list_reference '_pd_calib_detector_id'
_units deg
_units_detail 'degree of arc'
_enumeration_range -180.0:180.0
_definition
; _pd_calib_2theta_offset defines an offset angle (in degrees)
used to calibrate 2\q (as defined in _pd_meas_2theta_).
Calibration is done by adding the offset:
2\q~calibrated~ = 2\q~measured~ + 2\q~offset~
For cases where the _pd_calib_2theta_offset value is
not a constant, but rather varies with 2\q, a set
of offset values can be supplied in a loop. In this case,
the value where the offset has been determined can be
specified as _pd_calib_2theta_off_point. Alternatively, a
range where the offset is applicable can be specified using
_pd_calib_2theta_off_min and _pd_calib_2theta_off_max.
;
data_pd_calib_detector_id
_name '_pd_calib_detector_id'
_category pd_calib
_type char
_list yes
_list_mandatory yes
_list_link_child '_pd_meas_detector_id'
_definition
; A code which identifies the detector or channel number in a
position-sensitive, energy-dispersive or other multiple-detector
instrument. Note that this code should match the code name used
for _pd_meas_detector_id.
;
data_pd_calib_detector_response
_name '_pd_calib_detector_response'
_category pd_calib
_type numb
_list yes
_list_reference '_pd_calib_detector_id'
_enumeration_range 0.0:
_definition
; A value that indicates the relative sensitivity of each
detector. This can compensate for differences in electronics,
size and collimation. Usually, one detector or the mean for
all detectors will be assigned the value of 1.
;
data_pd_calib_std_external_
loop_ _name '_pd_calib_std_external_block_id'
'_pd_calib_std_external_name'
_category pd_calib
_type char
_list both
_list_reference '_pd_calib_detector_id'
_definition
; Identifies the data set used as an external standard for
the diffraction angle or the intensity calibrations.
*_name specifies the name of the material and
*_id the _pd_block_id for the CIF containing calibration
measurements. If more than one data set is used for
calibration, these fields may be looped.
;
data_pd_calib_std_internal_mass_%
_name '_pd_calib_std_internal_mass_%'
_category pd_calib
_type numb
_type_conditions esd
_list both
_list_reference '_pd_calib_detector_id'
_enumeration_range 0.0:100.0
_definition
; Per cent presence of the internal standard specified by the
data item _pd_calib_std_internal_name expressed as 100 times
the ratio of the amount of standard added to the original
sample mass.
;
data_pd_calib_std_internal_name
_name '_pd_calib_std_internal_name'
_category pd_calib
_type char
_list both
_list_reference '_pd_calib_detector_id'
loop_ _example 'NIST 640a Silicon standard'
'Al2O3'
_definition
; Identity of material(s) used as an internal intensity standard.
;
data_pd_calibration_conversion_eqn
_name '_pd_calibration_conversion_eqn'
_category pd_calibration
_type char
_example
; 2\q~actual~ = 2\q~setting~ + arctan(
cos(P~1~) / {1/[P~0~ (CC - CH~0~ - P~2~ CC^2^)] - sin(P~1~)} )
;
_definition
; The calibration function for converting a channel number
supplied in _pd_meas_detector_id for a position-sensitive
or energy-dispersive detector or the distance supplied in
_pd_meas_position to Q, energy, angle etc.
Use _pd_calib_std_external_ to define a pointer
to the file or data block containing the information used
to define this function.
;
data_pd_calibration_special_details
_name '_pd_calibration_special_details'
_category pd_calibration
_type char
_definition
; Description of how the instrument was
calibrated, particularly for instruments where
calibration information is used to make hardware
settings that would otherwise be invisible once data
collection is completed. Do not use this item to specify
information that can be specified using other _pd_calib_
items.
;
#............................ Specimen parameters
data_pd_spec_[pd]
_name '_pd_spec_[pd]'
_category category_overview
_type null
loop_
_example
_example_detail
#----------------------------------------------------------------------------
;
_pd_spec_mounting ?
_pd_spec_mount_mode transmission
_pd_spec_orientation horizontal
_pd_spec_preparation ?
;
;
Example 1.
;
#----------------------------------------------------------------------------
_definition
; This section contains information about the specimen used
for measurement of the diffraction data set. Note that
information about the sample (the batch of material from which
the specimen was obtained) is specified in _pd_prep_.
;
data_pd_spec_description
_name '_pd_spec_description'
_category pd_spec
_type char
_definition
; A description of the specimen, such as the source of the
specimen, identification of standards, mixtures etc.
;
data_pd_spec_mount_mode
_name '_pd_spec_mount_mode'
_category pd_spec
_type char
loop_ _enumeration reflection
transmission
_definition
; A code describing the beam path through the specimen.
;
data_pd_spec_mounting
_name '_pd_spec_mounting'
_category pd_spec
_type char
loop_ _example 'vanadium can with He exchange gas'
'quartz capillary'
'packed powder pellet'
'drifted powder on off-cut Si'
'drifted powder on Kapton film'
_definition
; A description of how the specimen is mounted.
;
data_pd_spec_orientation
_name '_pd_spec_orientation'
_category pd_spec
_type char
loop_ _enumeration horizontal
vertical
both
_definition
; The orientation of the \w (\q) and 2\q axis.
Note that this axis is parallel to the specimen axial axis
and perpendicular to the plane containing the incident and
scattered beams.
Thus for a horizontal orientation, scattering
measurements are made in a plane perpendicular to the
ground (the 2\q axis is parallel to the ground);
for vertical orientation, scattering measurements are
made in a plane parallel with the ground (the 2\q axis
is perpendicular to the ground). `Both' is appropriate for
experiments where measurements are made in both planes,
for example using two-dimensional detectors.
;
data_pd_spec_preparation
_name '_pd_spec_preparation'
_category pd_spec
_type char
loop_ _example 'wet grinding in acetone'
'sieved through a 44 micron (325 mesh/inch) sieve'
'spray dried in water with 1% clay'
_definition
; A description of the preparation steps for producing the
diffraction specimen from the sample. Include any procedures
related to grinding, sieving, spray drying etc. For
information relevant to how the sample is synthesized, use
the _pd_prep_ entries.
;
data_pd_spec_shape
_name '_pd_spec_shape'
_category pd_spec
_type char
loop_ _enumeration cylinder
flat_sheet
irregular
_definition
; A code describing the specimen shape.
;
data_pd_spec_size_
loop_ _name '_pd_spec_size_axial'
'_pd_spec_size_equat'
'_pd_spec_size_thick'
_category pd_spec
_type numb
_units mm
_units_detail millimetre
_enumeration_range 0.0:
_definition
; The size of the specimen in three mutually perpendicular
directions in millimetres.
The perpendicular to the plane containing the incident
and scattered beam is the *_axial direction.
In transmission geometry, the scattering vector is parallel
to *_equat and in reflection geometry the scattering vector is
parallel to *_thick.
;
data_pd_spec_special_details
_name '_pd_spec_special_details'
_category pd_spec
_type char
_definition
; Descriptive information about the specimen that cannot be
included in other data items.
;
#............................ Instrument parameters
data_pd_instr_[pd]
_name '_pd_instr_[pd]'
_category category_overview
_type null
loop_