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8. Atomic radii used in PLATON
Ac 1.88 Er 1.73 Na 0.97 Sb 1.46
Ag 1.59 Eu 1.99 Nb 1.48 Sc 1.44
Al 1.35 F 0.64 Nd 1.81 Se 1.22
Am 1.51 Fe 1.34 Ni 1.50 Si 1.20
As 1.21 Ga 1.22 Np 1.55 Sm 1.80
Au 1.50 Gd 1.79 O 0.68 Sn 1.46
B 0.83 Ge 1.17 Os 1.37 Sr 1.12
Ba 1.34 H 0.23 P 1.05 Ta 1.43
Be 0.35 Hf 1.57 Pa 1.61 Tb 1.76
Bi 1.54 Hg 1.70 Pb 1.54 Tc 1.35
Br 1.21 Ho 1.74 Pd 1.50 Te 1.47
C 0.68 I 1.40 Pm 1.80 Th 1.79
Ca 0.99 In 1.63 Po 1.68 Ti 1.47
Cd 1.69 Ir 1.32 Pr 1.82 Tl 1.55
Ce 1.83 K 1.33 Pt 1.50 Tm 1.72
Cl 0.99 La 1.87 Pu 1.53 U 1.58
Co 1.33 Li 0.68 Ra 1.90 V 1.33
Cr 1.35 Lu 1.72 Rr 1.47 W 1.37
Cs 1.67 Mg 1.10 Re 1.35 Y 1.78
Cu 1.52 Mn 1.35 Rh 1.45 Yb 1.94
D 0.23 Mo 1.47 Ru 1.40 Zn 1.45
Dy 1.75 N 0.68 S 1.02 Zr 1.56
Note: OW is equivalent to O and Q1 is equivalent to C1.
Covalent radii are those given in the Cambridge Structural data base manual.
9. Internal parameters
The program contains internal integer and real parameter arrays (IPR and PAR respectively).
They include default parameter settings and values that may be either explicitly or implicitly
manipulated with the (sub)keywords. Below is a list of some of them. Their values may be
changed with SET PAR and SET IPR instructions or examined with LIST PAR and LIST IPR
instructions. It should be noted that there is no checking for side-effects.
IPR(141) - Nplane parameter in TME
IPR(142) - Lines parameter in TME
PAR(73) - Letter size
10. CIF-validation documentation (VALIDATION.DOC)
This document should provide information on the CIF-validation tests as
specified in the file 'check.def' and implemented in PLATON.
# check.def contains the tests, error thresholds and warning messages
# issued by the program PLATON when run in the 'VALIDATION' mode
#
# This file is read when PLATON is called with the '-u' switch
# (e.g. 'platon -u sk1500.cif')
#
# - Test output will be in the order as defined implicitly below
#
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# - Tests are identified with three-digit numbers
# _0xx - general
# _1xx - cell/symmetry
# _2xx - adp-related
# _3xx - intra geometry
# _4xx - inter geometry
# _5xx - coordination geometry
# _6xx - void tests
# _7xx – various test
#
_000-_013 : Pseudo Requests
This set of pseudo requests generates a listing of some relevant reported
and calculated data including transmission range and completeness of the
data set.
_020 : Check on R(int)
R(int) should be well below 10% and in the order of magnitude of the
reported R-values. R(int) may be relatively meaningless when based on a
very limited number of averaged data.
_021 : Check ratio of observed/expected number of reflections
The expected number of reflections corresponds to that in the asymmmetric
unit of the Laue group.
Expected ratio: less-or-equal 1 for centro symmetric structures and
less than 2 for non-centrosymmetric structures.
Reasons to exceed those numbers can be:
1 - Systematic extinction not omitted from the observed data count
2 - Refinement with redundant (i.e. not averaged/unique) data set.
_022 : Check for completeness
Test for data completeness. The ratio of the reported number of unique
reflections and expected for the resolution given.
_023 : Check Theta-max
Check resolution of the data set. Alerts are issued when sin(theta)/lambda
< 0.6
_024 : Check for Friedel Averaging Preferred
Averaging of Friedel pairs is preferred for MoKa datasets containing atoms
not heavier than Si. Use MERG 4 for SHELXL97 refinements.
_025 : Check h,k,l - range
Check reported h,k,l - range with calculated range based on reported theta-
max.
_026 : Check for weak data
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32
Check whether a sufficient fraction of the unique data is indeed above the
2 sigma level.
_030 Check on meaningfully refined extinction parameter.
This test checks whether a refined extinction parameter is meaningful i.e.
whether its value is significantly larger than its corresponding s.u. If
not, this parameter should be removed from the model and the structure
refined without this meaningless additional parameter. The current default
gives a warning when it value is within 3.33 s.u.
_032 Check S.U. of the Flack parameter
Check meaningfulness of Flack parameter
_033 Check deviation of Flack parameter from zero
Check validity of absolute stucture determination
_040 Check for the presence of H-atoms in carbon containing compounds.
Alert for 'no H-atoms' in CIF
_041 Compare the Reported and Calculated Sum Formula
_042 Compare the reported and Calculated Moiety Formula
_043 Compare Reported and Calculated Molecular Weight
Note: atomic weights used in the calculation of the molecular weight are
those used in SHELXL97.
_044 Compare Reported and Calculated density
_045 Compare Reported and Calculated Z
_046 Check on Reported Z, MW, D(calc) consistency
D(calc) as calculated from the reported Z and MW is compared for
consistency with the reported d(calc).
_050 Test for mu given
_051 Test diference of reported and calculated mu
_052 Test for specification of absorption correction method