114
P. R. P. Barreto et al.
Table 4 The electric properties dipole moment (μ), polarizability (α), quadrupole moment (θ),
ionization potential, electron affinity and proton affinity, calculated for the propylene oxide–raregas atoms systems, and zero point energy (ZPE) for the propylene oxide molecule, compared with
reference data
μ
(D)
α (a.
u.)
θ (a.
u.)
Ionization
potential
(eV)
Electron
affinity
(eV)
Proton
affinity
(kcal/mol)
ZPE
(kcal/mol)
He
1.38
24.56
2.63
37.1
1.40
24.59
42.5
[26]
[27]
[28]
Ne
2.59
21.53
5.28
42.3
2.57
21.57
47.5
[26]
[27]
[28]
Ar
11.08
15.74
2.76
84.9
11.23
15.76
88.2
[26]
[27]
[28]
C 3 H 6 O
2.32
36.11
43.50
9.07
2.15
175.3
53.3823
2.01
10.22 ± 0.02
192.0
[29]
[30]
[28]
it becomes attractive in the vicinity of the potential-well, where the dispersion and
exchange forces play the most important role, thus the contribution of the electrostatic interactions is almost negligible. Even lower is the effect of induction forces,
whose attractive character becomes relevant in the short range of distances, where
the repulsive contribution of the exchange forces conceals all the other contributions.
Table 4 compares the minimum obtained from ab initio and SAPT calculation for
the configuration F1. The energies obtained by the SAPT and ab initio method with
counterpoise correction present a good agreement, with an error lower than 1% in
energy.
4 Final Remarks
The interaction potential of fourteen configurations of the systems propylene oxide–
rare-gas-atoms (He, Ne and Ar) have been calculated at the CCSDT(t) level of theory,
using the aug-cc-pVDZ basis set. The geometry of propylene oxide, modeled as rigid,
has been optimized at various levels of theory and CBS-Q3 gave the best agreement
with reference data. The analytical form of the potential energy surface is generated
by fitting the single point energies with a fifth-order generalize Rydberg potential
function. The potential energy profiles of the three systems present a similar trend and
F1 is the most stable leading configuration for all the three rare-gases. As expected,
P. R. P. Barreto et al.
Table 4 The electric properties dipole moment (μ), polarizability (α), quadrupole moment (θ),
ionization potential, electron affinity and proton affinity, calculated for the propylene oxide–raregas atoms systems, and zero point energy (ZPE) for the propylene oxide molecule, compared with
reference data
μ
(D)
α (a.
u.)
θ (a.
u.)
Ionization
potential
(eV)
Electron
affinity
(eV)
Proton
affinity
(kcal/mol)
ZPE
(kcal/mol)
He
1.38
24.56
2.63
37.1
1.40
24.59
42.5
[26]
[27]
[28]
Ne
2.59
21.53
5.28
42.3
2.57
21.57
47.5
[26]
[27]
[28]
Ar
11.08
15.74
2.76
84.9
11.23
15.76
88.2
[26]
[27]
[28]
C 3 H 6 O
2.32
36.11
43.50
9.07
2.15
175.3
53.3823
2.01
10.22 ± 0.02
192.0
[29]
[30]
[28]
it becomes attractive in the vicinity of the potential-well, where the dispersion and
exchange forces play the most important role, thus the contribution of the electrostatic interactions is almost negligible. Even lower is the effect of induction forces,
whose attractive character becomes relevant in the short range of distances, where
the repulsive contribution of the exchange forces conceals all the other contributions.
Table 4 compares the minimum obtained from ab initio and SAPT calculation for
the configuration F1. The energies obtained by the SAPT and ab initio method with
counterpoise correction present a good agreement, with an error lower than 1% in
energy.
4 Final Remarks
The interaction potential of fourteen configurations of the systems propylene oxide–
rare-gas-atoms (He, Ne and Ar) have been calculated at the CCSDT(t) level of theory,
using the aug-cc-pVDZ basis set. The geometry of propylene oxide, modeled as rigid,
has been optimized at various levels of theory and CBS-Q3 gave the best agreement
with reference data. The analytical form of the potential energy surface is generated
by fitting the single point energies with a fifth-order generalize Rydberg potential
function. The potential energy profiles of the three systems present a similar trend and
F1 is the most stable leading configuration for all the three rare-gases. As expected,