|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Aluminum
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Introduction
|
|
|
|
|
|
|
|
|
|
|
|
|
|
In
the Table that follows, RSD is the residual standard deviation of the
linear regression analysis of the calculated efg's versus the
experimental nqcc's for the molecules given on the previous
page.
This may be taken as a conservative estimate of the
uncertainty
in the calculated nqcc's. (Note: A RSD of 0.22 MHz is 1 % of
the
average absolute experimental nqcc for the molecules used for
calibration.) All three diagonal components of the efg
tensors
are plotted against the corresponding components of the experimental
nqcc tensors. This assures, because the tensors are traceless, that the
linear regression line pass through the origin. The slope of
this
line is eQeff/h from which the value
of Qeff is extracted. Qeff
is the model
dependent nuclear electric quadrupole moment effective
for calculation of the nqcc's. For comparison, the currently
recommended Q for 27Al
is 146.6(10) mb.
It is our goal to reproduce accurately as well as efficiently
the
experimental nqcc's - not Q. It is sufficient - indeed, all that can be
expected at the level of theory in this work - that Qeff
and
Q agree to within a few percent. |
|
|
|
|
|
|
|
|
|
|
|
|
|
For
the Dunning correlation consistent basis sets, EMSL indicates that the
source of the bases is the online EMSL basis set library. |
|
|
|
|
|
|
|
|
|
|
|
|
|
Polarization
and diffuse functions used with the Alhrichs TZV bases are those
developed for use with the Pople type bases. The 6-311G(2d)
and
TZV(2d) bases, for example, contain the same polarization functions -
same exponents and coefficients. |
|
|
|
|
|
|
|
|
|
|
|
|
|
With
the MP2 method, FC = frozen core, and FULL = all electron correlation.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Table
1. Calibration RSD (MHz) and
Qeff (mb). |
|
|
|
|
|
Method/aug-cc-pCVQZ(Al)/aug-cc-pVQZ
(EMSL) |
|
|
|
|
|
|
RSD
|
Qeff
|
|
|
|
|
|
HF
|
0.24
|
131.36(39)
|
|
B1LYP
|
0.39
|
135.90(65)
|
|
mPW1PW91
|
0.41
|
138.16(69)
|
|
|
|
|
|
Method/aug-cc-pCVTZ(Al)/aug-cc-pVTZ
(EMSL) |
|
|
|
|
|
HF
|
0.24
|
132.16(39)
|
|
MP2(FC)
|
0.38
|
142.47(67)
|
|
MP2(FULL)
|
0.38
|
142.46(66)
|
|
B1LYP
|
0.42
|
135.92(71)
|
|
B3LYP
|
0.46
|
136.46(77)
|
|
mPW1PW91
|
0.46
|
139.02(79)
|
|
PBE1PBE
|
0.48
|
139.32(82)
|
|
B98
|
0.47
|
138.72(80)
|
|
|
|
|
|
Method/aug-cc-pCVDZ(Al)/aug-cc-pVDZ
(EMSL) |
|
|
|
|
|
HF
|
0.13
|
138.71(23)
|
|
MP2(FULL)
|
0.51
|
153.15(97)
|
|
B1LYP
|
0.51
|
144.02(90)
|
|
mPW1PW91
|
0.51
|
144.79(91)
|
|
|
|
|
|
HF/aug-cc-pVDZ
(EMSL) |
0.35
|
168.70(73)
|
|
HF/cc-pCVDZ/cc-pVDZ
(EMSL) |
0.45
|
140.08(78)
|
|
|
|
|
|
Alhrichs' bases
|
|
|
|
|
|
HF/TZVP
|
0.25
|
127.90(40)
|
|
MP2(FULL)/TZVP
|
0.41
|
135.61(69)
|
|
B1LYP/TZVP
|
0.49
|
131.01(79)
|
|
mPW1PW91/TZVP
|
0.54
|
134.69(91)
|
|
HF/TZV(2d)
|
0.13
|
127.51(20)
|
|
MP2(FULL)/TZV(2d)
|
0.55
|
135.09(92)
|
|
B1LYP/TZV(2d)
|
0.56
|
130.09(91)
|
|
mPW1PW91/TZV(2d)
|
0.61
|
133.5(10)
|
|
|
|
|
|
Pople bases
|
|
|
|
|
|
|
|
HF/6-311G(2d)
|
0.22
|
131.96(35)
|
|
MP2(FULL)/6-311G(2d)
|
0.36
|
141.20(62)
|
|
B1LYP/6-311G(2d)
|
0.43
|
136.58(72)
|
|
mPW1PW91/6-311G(2d)
|
0.47
|
138.41(80)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Go back
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Table
of Contents
|
|
|
|
|
|
|
Molecules/Aluminum
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|