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Chlorine
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Calibration
of the
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B1LYP/TZV(3df,2p)
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model |
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This
is the recommended model, calibration statistics for which are
shown below.
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Calibration
was made by linear regression analysis of
calculated electric field gradients vs experimental nuclear quadrupole
coupling constants.
Calculations of the field gradients were made
on the equilibrium structures of the following molecules: |
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Figure
1. PDF
Calculated efg's
vs experimental nqcc's.
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35Cl
Calibration
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Number
of
Points
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66
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Correlation
Coefficient
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0.99996
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Residual
Standard Deviation
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0.49 MHz (1.1
%)
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Slope, eQeff/h
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-19.166(21)
MHz/a.u.
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Qeff |
-81.568(91) mb
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Q
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-81.65(80) mb
[1]
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Qeff
differs from Q by 0.10
%. Using Qeff for conversion of the
calculated efg's
to nqcc's yields for these 22 molecules a root mean square (RMS)
difference between calculated and experimental nqcc's of 0.481
MHz. Essentially the same RMS difference is obtained using Q,
namely 0.484 MHz. Therefore, for calculation of the chlorine
nqcc's (both isotopes), we use eQ/h rather than eQeff/h:
that is, for 35Cl,
eQ/h = -19.185 MHz/a.u.,
and for 37Cl,
-15.120 MHz/a.u. |
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37Cl
Calibration |
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Number
of
Points
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51 *
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Correlation
Coefficient
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0.99996
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Residual
Standard Deviation
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0.44 MHz (1.1
%)
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Slope, eQeff/h
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-15.106(20)
MHz/a.u.
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Qeff |
-64.292(86) mb
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Q
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-64.35(64) mb
[1]
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*
No
experimental nqcc's for BCl, CH2Cl2,
CH2CCl2,
SiH2Cl2,
and Cl2O. |
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Reference
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[1]
P.Pyykkö and
J.Li, 1992 Nuclear
Quadrupole Moments, Report HUKI 1-92, ISSN 0784-0365. |
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"Nuclear
quadrupole coupling constants in alkali halide molecules: an ab
initio quantum chemical study" G.B.Bacskay and
A.D.Buckingham,
Mol.Phys. 91,391(1997). |
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"Halogen
Nuclear Quadrupole Coupling Constants: Comparison of ab initio
Calculations which
include Correlation with Experiment" M.H.Palmer, J.A.Blair-Fish,
P.Sherwood, and M.F.Guest, Z.Naturforsch. 53a,383(1998).
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Table
of Contents
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Chlorine Molecules
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