Chemistry Reference
In-Depth Information
Table 11.4 N-term convergence of ground-state isotropic dipole polarizabilities
a
ð
a
0
Þ
for simple atoms and molecules
H
2
a
H
2
b
N
H
He
1
4
0.694
1.485
2.523
2
4.5
1.042
2.614
3.481
3
1.078
2.819
3.493
4
1.082
2.836
4.078
5
1.135
2.837
4.452
10
1.364
2.855
4.999
15
1.378
2.864
5.145
20
1.382
2.864
5.165
4.5
c
1.383
d
2.864
e
5.181
f
Accurate
a
H
2
: R
e
¼
2a
0
.
b
H
2
: R
e
¼
1
4a
0
.
c
Exact value.
d
Yan et al., 1996.
e
Bishop and Cheung, 1978; Babb, 1994; Magnasco and Ottonelli, 1999b.
f
Bishop et al., 1991.
:
value (0.099) by 2%. So, these homo- and hetero-dimer calculations are
affected essentially by the same percent errors
6
.
Tables 11.4 and 11.5 show, respectively, the convergence of N-term
dipole pseudospectra in the calculation of polarizabilities
a
and isotropic
Table 11.5 N-term convergence of isotropic C
6
dispersion coefficients
ð
E
h
a
0
Þ
for the
homodimers of simple atoms and molecules
H
2
-- H
2
a
H
2
-H
2
b
N
H-H
He-He
1
6
0.695
1.449
4.729
2
6.482
1.142
2.965
7.325
3
6.498
1.186
3.218
7.364
4
6.499
1.189
3.234
8.825
5
6.499
1.242
3.234
9.645
10
1.443
3.265
10.965
15
1.455
3.284
11.263
20
1.459
3.284
11.289
6.499
c
1.461
d
3.284
e
11.324
f
Accurate
a
H
2
þ
: R
e
¼
2a
0
.
b
H
2
: R
e
¼
1
:
4a
0
.
c
Exact value.
d
Yan et al., 1996.
e
Babb, 1994; Magnasco and Ottonelli, 1999b.
f
Magnasco and Ottonelli, 1996a.
6
These errors are completely removed when using best four-term reduced pseudospectra for H
and H
2
obtained from a recently derived efficient interpolation technique (Figari et al., 2007).
