A new approach to the electron correlation problem based on phase space intracules derived from the Wigner distribution is applied to excited states. The computed electron correlation energy reduces the mean absolute error in the prediction of the excitation energies of 55 atomic excited states from 0.65eV for unrestricted Hartree-Fock to 0.32eV. This compares favorably to a mean absolute deviation of 0.52eV for second order Møller-Plesset perturbation theory and 0.35eV for the Lee-Yang-Parr functional. An analogous correlation model based on the Husimi distribution is developed. Predicted correlation energies and excitation energies from this model are significantly worse than for the Wigner intracule based model. Alternative correlation kernels may be more suitable for the Husimi intracule based approach.

1.
M.
Schütz
and
H.-J.
Werner
,
J. Chem. Phys.
114
,
661
(
2001
).
2.
A. D.
Becke
,
J. Chem. Phys.
98
,
1372
(
1993
).
3.
P. J.
Stephens
,
F. J.
Devlin
,
C. F.
Chabalowski
, and
M. J.
Frisch
,
J. Chem. Phys.
98
,
11623
(
1994
).
4.
P. M. W.
Gill
,
D. L.
Crittenden
,
D. P.
O’Neill
, and
N. A.
Besley
,
Phys. Chem. Chem. Phys.
8
,
15
(
2006
).
5.
E.
Wigner
,
Phys. Rev.
40
,
749
(
1932
).
6.
H. J.
Groenewold
,
Physica (Amsterdam)
12
,
405
(
1946
).
7.
P. M. W.
Gill
,
D. P.
O’Neill
, and
N. A.
Besley
,
Theor. Chem. Acc.
109
,
241
(
2003
).
8.
N. A.
Besley
,
D. P.
O’Neill
, and
P. M. W.
Gill
,
J. Chem. Phys.
118
,
2033
(
2003
).
9.
N. A.
Besley
and
P. M. W.
Gill
,
J. Chem. Phys.
120
,
124
(
2004
).
10.
V. A.
Rassolov
,
J. Chem. Phys.
110
,
3672
(
1999
).
11.
K.
Husimi
,
Proc. Phys. Math. Soc. Jpn.
22
,
264
(
1940
).
12.
J. E.
Harriman
,
J. Chem. Phys.
88
,
6399
(
1988
).
13.
N. A.
Besley
,
Chem. Phys. Lett.
409
,
63
(
2005
).
14.
S. F.
Boys
,
Proc. R. Soc. London, Ser. A
200
,
542
(
1950
).
15.
J.
Kong
,
C. A.
White
,
A. I.
Krylov
 et al,
J. Comput. Chem.
21
,
1532
(
2000
).
16.
Y.
Ralchenko
,
F.-C.
Jou
,
D. E.
Kelleher
,
A. E.
Kramida
,
A.
Musgrove
,
J.
Reader
,
W. L.
Wiese
, and
K.
Olsen
,
NIST Atomic Spectra Database, Version 3.0.3
,
National Institute of Standards and Technology
, Gaithersburg, MD,
2005
.
17.
A. T. B.
Gilbert
,
G. B. W.
Gill
, and
P. M. W.
Gill
, (unpublished).
18.
T. H.
Dunning
, Jr.
,
J. Chem. Phys.
90
,
1007
(
1989
).
19.
R. A.
Kendall
,
T. H.
Dunning
, Jr.
, and
R. J.
Harrison
,
J. Chem. Phys.
96
,
6796
(
1992
).
20.
D. E.
Woon
and
T. H.
Dunning
, Jr.
,
J. Chem. Phys.
98
,
1358
(
1993
).
21.
D. E.
Woon
and
T. H.
Dunning
, Jr.
,
J. Chem. Phys.
100
,
2975
(
1994
).
22.
H.-J.
Werner
,
P. J.
Knowles
,
R.
Lindh
 et al, MOLPRO a package of ab initio programs.
23.
M.
Filatov
and
S.
Shaik
,
Chem. Phys. Lett.
288
,
599
(
1998
).
24.
M.
Filatov
and
S.
Shaik
,
J. Chem. Phys.
110
,
116
(
1999
).
25.
C.
Lee
,
W.
Yang
, and
R. G.
Parr
,
Phys. Rev. B
37
,
785
(
1988
).
26.
D. J.
Tozer
and
N. C.
Handy
,
J. Chem. Phys.
109
,
10180
(
1998
).
27.
A. D.
Dreuw
,
J. L.
Weisman
, and
M.
Head-Gordon
,
J. Chem. Phys.
119
,
2943
(
2003
).
28.
Y.
Tawada
,
T.
Tsuneda
,
S.
Yanagisawa
,
T.
Yanai
, and
K.
Hirao
,
J. Chem. Phys.
120
,
8425
(
2004
).
29.
D. P.
O’Neill
and
P. M. W.
Gill
,
Mol. Phys.
103
,
763
(
2005
).
You do not currently have access to this content.