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55 does satisfy the stationarity equation with an accuracy better
v ¼
7
:
10 5 . In the following, however, we shall content ourselves with
the rounded value v
than 1
8 , which means 2% mixing of s into the bond
hybrid (98% p). In the range 7 v
8 jbj
has the practically constant
value
7 kcal mol 1
jbj¼
0
:
1142 E h
¼
71
:
:
2.7.2.4 Charge Distribution in the Hybridized Basis
We now analyse the charge distribution in ground state HF resulting from
the s bond orbitals in the hybridized basis (Figure 2.15):
2 s
l
¼
scos v
zsin v
ð
2
:
164
Þ
b
h
l
þl
ssin
zcos vþl
h
3 s
p
¼
p
ð
:
Þ
l
2
165
2
2
þ
1
þ
1
We have for the electron density (Magnasco, 2007, Magnasco, 2009a):
<
2
2
P
ðrÞ¼
2
½
2 s ðÞ
þ
2
½
3 s ðÞ
z 2 sin 2 v
s 2 cos 2
¼
2
½
sz sin2 v
Þ 1
2
s 2 sin 2
z 2 cos 2
2 h 2
þðl
þ
1
ð
szsin 2 vþl
Þ
s 2 2 cos 2
z 2 2 sin 2
h 2 2
2sin 2 v
l
2
2cos 2 v
l
l
:
¼
þ
þ
2
2
2
þ
1
þ
1
l
þ
1
sz
2
2sin2 v l
þ
2
l
þ
1
ð
2
:
166
Þ
where the first three terms contribute to the heteropolar dipole ( m H ), the
last term being the contribution from the so called atomic dipole m A
(Coulson, 1961). There is no contribution from the size effect (or homo-
polar) dipole moment, since we are neglecting explicit overlap between
our AOs. Of course, the conservation relation holds:
ð d r P
ðrÞ¼
4
ð
2
:
167
Þ
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