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-
- 1
-
J. Cízek, J. Chem. Phys., 45, 4256 (1966).
On the correlation problem in atomic and molecular systems. Calculation of
wavefunction components in Ursell-type expansion using quantum-field
theoretical methods.
- 2
-
J. Cízek, Adv. Chem. Phys., 14, 35 (1969).
On the use of the cluster expansion and the technique of diagrams in
calculations of correlation effects in atoms and molecules.
- 3
-
J. Cízek and J. Paldus, Int. J. Quantum Chem., 5, 359
(1971).
Correlation problems in atomic and molecular systems. III. Rederivation of the
coupled-pair many-electron theory using the traditional quantum chemical
methods.
- 4
-
A. C. Hurley, Electron Correlation in Small Molecules, Academic Press,
London, 1976.
- 5
-
H. J. Monkhorst, Int. J. Quantum Chem. Symp., 11, 421 (1977).
Calculation of properties with the coupled-cluster method.
- 6
-
J. A. Pople, R. Krishnan, H. B. Schlegel, and J. S. Binkley, Int. J.
Quantum Chem. Symp., 14, 545 (1978).
Electron correlation theories and their application to the study of simple
reaction potential surfaces.
- 7
-
R. J. Bartlett and G. D. Purvis, Int. J. Quantum Chem., 14, 561
(1978).
Many-body perturbation theory, coupled-pair many-electron theory, and the
importance of quadruple excitations for the correlation problem.
- 8
-
G. D. Purvis and R. J. Bartlett, J. Chem. Phys., 76, 1910 (1982).
A full coupled-cluster singles and doubles model: The inclusion of disconnected
triples.
- 9
-
G. D. Purvis and R. J. Bartlett, J. Chem. Phys., 75, 1284 (1981).
The reduced linear equation method in coupled cluster theory.
- 10
-
G. E. Scuseria, T. J. Lee, and H. F. Schaefer, Chem. Phys. Lett., 130, 236 (1986).
Accelerating the convergence of the coupled-cluster approach. The use of the
DIIS method.
- 11
-
G. E. Scuseria, A. C. Scheiner, T. J. Lee, J. E. Rice, and H. F. Schaefer, J. Chem. Phys., 86, 2881 (1987).
The closed-shell coupled-cluster single and double excitation (CCSD) model
for the description of electron correlation. A comparison with
configuration interaction (CISD) results.
- 12
-
T. J. Lee and J. E. Rice, Chem. Phys. Lett., 150, 406 (1988).
An efficient closed-shell singles and doubles coupled-cluster method.
- 13
-
G. E. Scuseria, C. L. Janssen, and H. F. Schaefer, J. Chem. Phys., 89, 7382 (1988).
An efficient reformulation of the closed-shell coupled-cluster single and
double excitation (CCSD) equations.
- 14
-
J. F. Stanton, J. Gauss, J. D. Watts, and R. J. Bartlett, J. Chem. Phys.,
94, 4334 (1991).
A direct product decomposition approach for symmetry exploitation in many-body
methods. I. Energy calculations.
- 15
-
R. J. Bartlett, H. Sekino, and G. D. Purvis, Chem. Phys. Lett., 98,
66 (1983).
Comparison of MBPT and coupled-cluster methods with full CI. Importance
of triplet excitations and infinite summations.
- 16
-
Y. S. Lee, S. A. Kucharski, and R. J. Bartlett, J. Chem. Phys., 81,
5906 (1984).
A coupled-cluster approach with triple excitations.
- 17
-
J. A. Pople, M. Head-Gordon, and K. Raghavachari, J. Chem. Phys., 87, 5968 (1987).
Quadratic configuration interaction. A general technique for determining
electron correlation energies.
- 18
-
M. Urban, J. Noga, S. J. Cole, and R. J. Bartlett, J. Chem. Phys., 83, 4041 (1985).
Towards a full CCSDT model for electron correlation.
- 19
-
M. R. Hoffmann and H. F. Schaefer, Adv. Quantum Chem., 18, 207
(1986).
A full coupled-cluster singles, doubles, and triples model for the description
of electron correlation.
- 20
-
S. A. Kucharski and R. J. Bartlett, Adv. Quantum Chem., 18, 281
(1986).
Fifth-order many-body perturbation theory and its relationship to various
coupled-cluster approaches.
- 21
-
J. Noga, R. J. Bartlett, and M. Urban, Chem. Phys. Lett., 134, 126
(1987).
Towards a full CCSDT model for electron correlation. CCSDT-n models.
- 22
-
J. Noga and R. J. Bartlett, J. Chem. Phys., 86, 7041 (1987),
erratum: 89, 3401 (1988).
The full CCSDT model for molecular electronic structure.
- 23
-
G. E. Scuseria and H. F. Schaefer, Chem. Phys. Lett., 152, 382
(1988).
A new implementation of the full CCSDT model for molecular electronic
structure.
- 24
-
K. Raghavachari, G. W. Trucks, J. A. Pople, and M. Head-Gordon, Chem.
Phys. Lett., 157, 479 (1989).
A fifth-order perturbation comparison of electron correlation.
- 25
-
R. J. Bartlett, J. D. Watts, S. A. Kucharski, and J. Noga, Chem. Phys.
Lett., 165, 513 (1990), erratum: 167, 609 (1990).
Non-iterative fifth-order triple and quadruple excitation energy corrections in
correlated methods.
- 26
-
J. D. Watts and R. J. Bartlett, J. Chem. Phys., 93, 6104 (1990).
The coupled-cluster single, double, and triple excitation model for open-shell
single reference functions.
- 27
-
G. E. Scuseria, Chem. Phys. Lett., 176, 27 (1991).
The open-shell restricted Hartree-Fock singles and doubles coupled-cluster
method including triple excitations CCSD(T): Application to C3+.
- 28
-
S. A. Kucharski and R. J. Bartlett, J. Chem. Phys., 97, 4282
(1992).
The coupled-cluster single, double, triple, and quadruple excitation method.
- 29
-
J. D. Watts, J. Gauss, and R. J. Bartlett, J. Chem. Phys., 98,
8718 (1993).
Coupled-cluster methods with noniterative triple excitations for restricted
open-shell Hartree-Fock and other general single determinant reference
functions. Energies and analytical gradients.
- 30
-
M. J. O. Deegan and P. J. Knowles, Chem. Phys. Lett., 227, 321
(1994).
Perturbative corrections to account for triple excitations in closed- and
open-shell coupled-cluster theories.
- 31
-
T. D. Crawford and H. F. Schaefer, J. Chem. Phys., 104, 6259
(1996).
A comparison of two approaches to perturbational triple excitation corrections
to the coupled-cluster singles and doubles method for high-spin open-shell
systems.
- 32
-
J. F. Stanton, Chem. Phys. Lett., 281, 130 (1997).
Why CCSD(T) works: A different perspective.
- 33
-
T. D. Crawford, T. J. Lee, and H. F. Schaefer, J. Chem. Phys., 107,
7943 (1997).
A new spin-restricted triple excitation correction for coupled cluster theory.
- 34
-
T. D. Crawford and J. F. Stanton, Int. J. Quantum Chem. Symp., in press.
Investigation of an asymmetric triple-excitation correction for coupled cluster
energies.
- 35
-
M. Rittby and R. J. Bartlett, J. Phys. Chem., 92, 3033 (1988).
An open-shell spin-restricted coupled-cluster method: Application to ionization
potentials in N2.
- 36
-
C. L. Janssen and H. F. Schaefer, Theor. Chim. Acta, 79, 1
(1991).
The automated solution of second quantization equations with applications to
the coupled-cluster approach.
- 37
-
P. J. Knowles, C. Hampel, and H.-J. Werner, J. Chem. Phys., 99,
5219 (1993).
Coupled-cluster theory for high-spin, open-shell reference wave functions.
- 38
-
P. Neogrády, M. Urban, and I. Hubac, J. Chem. Phys., 100,
3706 (1994).
Spin adapted restricted Hartree-Fock reference coupled-cluster theory for
open-shell systems.
- 39
-
X. Li and J. Paldus, J. Chem. Phys., 101, 8812 (1994).
Automation of the implementation of spin-adapted open-shell coupled-cluster
theories relying on the unitary group formalism.
- 40
-
X. Li and J. Paldus, J. Chem. Phys., 102, 2013 (1995).
Spin-adapted open-shell state-selective coupled-cluster approach and doublet
stability of its Hartree-Fock reference.
- 41
-
M. Nooijen and R. J. Bartlett, J. Chem. Phys., 104, 2652 (1996).
General spin adaptation of open-shell coupled cluster theory.
- 42
-
P. G. Szalay and J. Gauss, J. Chem. Phys., 107, 9028 (1997).
Spin-restricted open-shell coupled-cluster theory.
- 43
-
P. Jørgensen and J. Simons, J. Chem. Phys., 79, 334 (1983).
Ab initio analytical molecular gradients and Hessians.
- 44
-
L. Adamowicz, W. D. Laidig, and R. J. Bartlett, Int. J. Quantum Chem.
Symp., 18, 245 (1984).
Analytical gradients for the coupled-cluster method.
- 45
-
G. Fitzgerald, R. Harrison, W. D. Laidig, and R. J. Bartlett, Chem. Phys.
Lett., 117, 433 (1985).
Analytical gradient evaluation in coupled-cluster theory.
- 46
-
R. J. Bartlett, in Geometrical Derivatives of Energy Surfaces and
Molecular Properties, P. Jørgensen and J. Simons, Eds., D. Reidel,
Dordrecht, 1986, pp. 35-61.
Analytical evaluation of gradients in coupled-cluster and many-body
perturbation theory.
- 47
-
G. Fitzgerald, R. J. Harrison, and R. J. Bartlett, J. Chem. Phys., 85, 5143 (1986).
Analytic energy gradients for general coupled-cluster methods and fourth-order
many-body perturbation theory.
- 48
-
A. C. Scheiner, G. E. Scuseria, J. E. Rice, T. J. Lee, and H. F. Schaefer, J. Chem. Phys., 87, 5361 (1987).
Analytic evaluation of energy gradients for the single and double excitation
coupled cluster (CCSD) wave function: Theory and application.
- 49
-
E. A. Salter, G. W. Trucks, and R. J. Bartlett, J. Chem. Phys., 90,
1752 (1989).
Analytic energy derivatives in many-body methods. I. First derivatives.
- 50
-
J. Gauss, J. F. Stanton, and R. J. Bartlett, J. Chem. Phys., 95,
2623 (1991).
Coupled-cluster open-shell analytic gradients: Implementation of the direct
product decomposition approach in energy gradient calculations.
- 51
-
J. Gauss, W. J. Lauderdale, J. F. Stanton, J. D. Watts, and R. J. Bartlett,
Chem. Phys. Lett., 182, 207 (1991).
Analytic energy gradients for open-shell coupled-cluster singles and doubles
calculations using restricted open-shell Hartree-Fock (ROHF) reference
functions.
- 52
-
J. Gauss, J. F. Stanton, and R. J. Bartlett, J. Chem. Phys., 95,
2639 (1991).
Analytic evaluation of energy gradients at the coupled-cluster singles and
doubles level using quasi-restricted Hartree-Fock open-shell reference
functions.
- 53
-
G. E. Scuseria, J. Chem. Phys., 94, 442 (1991).
Analytic evaluation of energy gradients for the singles and doubles
coupled-cluster method including perturbative triple excitations: Theory and
applications to FOOF and Cr2.
- 54
-
T. J. Lee and A. P. Rendell, J. Chem. Phys., 94, 6229 (1991).
Analytic gradients for coupled-cluster energies that include noniterative
connected triple excitations: Application to cis- and trans-HONO.
- 55
-
E. A. Salter and R. J. Bartlett, J. Chem. Phys., 90, 1767 (1989).
Analytic energy derivatives in many-body theory. II. Second derivatives.
- 56
-
H. Koch, H. J. Aa. Jensen, P. Jørgensen, T. Helgaker, G. E. Scuseria, and
H. F. Schaefer, J. Chem. Phys., 92, 4924 (1990).
Coupled-cluster energy derivatives. Analytic Hessian for the closed-shell
coupled-cluster singles and doubles wave functions: Theory and applications.
- 57
-
J. F. Stanton and J. Gauss, in Recent Advances in Coupled-Cluster
Methods, R. J. Bartlett, Ed., World Scientific Publishing, Singapore, 1997,
pp. 49-79.
Analytic evaluation of second derivatives of the energy: Computational
strategies for the CCSD and CCSD(T) approximations.
- 58
-
J. Gauss and J. F. Stanton, Chem. Phys. Lett., 276, 70 (1997).
Analytic CCSD(T) second derivatives.
- 59
-
P. G. Szalay, J. Gauss, and J. F. Stanton, Theor. Chim. Acta, in press.
Analytic UHF-CCSD(T) second derivatives: Implementation and application to the
calculation of the vibration-rotation interaction constants of NCO and NCS.
- 60
-
D. Mukherjee and P. K. Mukherjee, Chem. Phys., 39, 325 (1979).
A response-function approach to the direct calculation of the transition-energy
in a multiple-cluster expansion formalism.
- 61
-
K. Emrich, Nucl. Phys. A, 351, 379 (1981).
An extension of the coupled cluster formalism to excited states (I).
- 62
-
S. Ghosh and D. Mukherjee, Proc. Indian Acad. Sci. (Chem. Sci.), 93, 947 (1984).
Use of cluster expansion techniques in quantum chemistry. A linear response
model for calculating energy differences.
- 63
-
H. Sekino and R. J. Bartlett, Int. J. Quantum Chem. Symp., 18, 255
(1984).
A linear response, coupled-cluster theory for excitation energy.
- 64
-
L. Meissner and R. J. Bartlett, J. Chem. Phys., 94, 6670 (1991).
Transformation of the Hamiltonian in excitation energy calculations: Comparison
between Fock-space multireference coupled-cluster and equation-of-motion
coupled-cluster methods.
- 65
-
J. F. Stanton and R. J. Bartlett, J. Chem. Phys., 98, 7029
(1993).
The equation of motion coupled-cluster method. A systematic biorthogonal
approach to molecular excitation energies, transition probabilities, and
excited state properties.
- 66
-
J. F. Stanton and J. Gauss, J. Chem. Phys., 99, 8840 (1993).
Many-body methods for excited state potential energy surfaces. I. General
theory of energy gradients for the equation-of-motion coupled-cluster method.
- 67
-
J. F. Stanton and J. Gauss, J. Chem. Phys., 101, 8938 (1994).
Analytic energy derivatives for ionized states described by the
equation-of-motion coupled-cluster method.
- 68
-
J. F. Stanton, J. Gauss, N. Ishikawa, and M. Head-Gordon, J. Chem. Phys.,
103, 4160 (1995).
A comparison of single reference methods for characterizing stationary points
of excited state potential energy surfaces.
- 69
-
H. Koch and P. Jørgensen, J. Chem. Phys., 93, 3333 (1990).
Coupled cluster response functions.
- 70
-
H. Koch, O. Christiansen, P. Jørgensen, and J. Olsen, Chem. Phys.
Lett., 244, 75 (1995).
Excitation energies of BH, CH2, and Ne in full configuration interaction and
the hierarchy CCS, CC2, CCSD, and CC3 of coupled-cluster models.
- 71
-
J. D. Watts, S. R. Gwaltney, and R. J. Bartlett, J. Chem. Phys., 105, 6979 (1996).
Coupled-cluster calculations of the excitation energies of ethylene, butadiene,
and cyclopentadiene.
- 72
-
O. Christiansen, H. Koch, A. Halkier, P. Jørgensen, T. Helgaker, and A. S.
de Merás, J. Chem. Phys., 105, 6921 (1996).
Large-scale calculations of excitation energies in coupled-cluster theory: The
singlet excited states of benzene.
- 73
-
M. Head-Gordon and T. J. Lee, in Recent Advances in Coupled-Cluster
Methods, R. J. Bartlett, Ed., World Scientific Publishing, Singapore, 1997,
pp. 221-253.
Single reference coupled cluster and perturbation theories of electronic
excitation energies.
- 74
-
M. Nooijen and R. J. Bartlett, J. Chem. Phys., 106, 6441 (1997).
A new method for excited states: Similarity transformed equation-of-motion
coupled-cluster theory.
- 75
-
O. Sinanoglu, Adv. Chem. Phys., 6, 315 (1964).
Many-electron theory of atoms, molecules, and their interactions.
- 76
-
R. J. Bartlett, J. Phys. Chem., 93, 1697 (1989).
Coupled-cluster approach to molecular structure and spectra: A step toward
predictive quantum chemistry.
- 77
-
R. J. Bartlett and J. F. Stanton, in Reviews in Computational Chemistry,
K. B. Lipkowitz and D. B. Boyd, Eds., VCH Publishers, New York, 1994, Vol. 5,
Chap. 2, pp. 65-169.
Applications of post-Hartree-Fock methods: A tutorial.
- 78
-
R. J. Bartlett, in Modern Electronic Structure Theory, Vol. 2 of Advanced Series in Physical Chemistry, D. R. Yarkony, Ed., World Scientific,
Singapore, 1995, Chap. 16, pp. 1047-1131.
Coupled-cluster theory: An overview of recent developments.
- 79
-
T. J. Lee and G. E. Scuseria, in Quantum Mechanical Electronic Structure
Calculations with Chemical Accuracy, S. R. Langhoff, Ed., Kluwer Academic
Publishers, Dordrecht, 1995, pp. 47-108.
Achieving chemical accuracy with coupled-cluster theory.
- 80
-
F. E. Harris, H. J. Monkhorst, and D. L. Freeman, Algebraic and
Diagrammatic Methods in Many-Fermion Theory, Oxford Press, New York, 1992.
- 81
-
P. R. Taylor, in Lecture Notes in Quantum Chemistry: European Summer
School II, Vol. 64 of Lecture Notes in Chemistry, B. O. Roos, Ed.,
Springer-Verlag, Berlin, 1994, Chap. 3, pp. 125-202.
Coupled-cluster methods in quantum chemistry.
- 82
-
A. Szabo and N. S. Ostlund, Modern Quantum Chemistry: Introduction to
Advanced Electronic Structure Theory, 1st ed., McGraw-Hill, New York, 1989.
- 83
-
W. Kutzelnigg, in Methods of Electronic Structure Theory, H. F.
Schaefer, Ed., Plenum Press, New York, 1977, pp. 129-188.
Pair-correlation theories.
- 84
-
P. Jørgensen and J. Simons, Second Quantization-Based Methods in
Quantum Chemistry, Academic Press, New York, 1981.
- 85
-
I. Shavitt, in Methods of Electronic Structure Theory, H. F. Schaefer,
Ed., Plenum Press, New York, 1977, pp. 189-275.
The method of configuration interaction.
- 86
-
C. D. Sherrill and H. F. Schaefer, Adv. Quantum Chem., in press.
The configuration interaction method: Advances in highly correlated approaches.
- 87
-
R. J. Bartlett, Annu. Rev. Phys. Chem., 32, 359 (1981).
Many-body perturbation theory and coupled-cluster theory for electron
correlation in molecules.
- 88
-
M. Nooijen, Ph.D. Thesis, Vrije Universiteit Amsterdam, 1992.
The coupled cluster Green's function.
- 89
-
J. A. Pople, in Energy, Structure, and Reactivity, D. W. Smith and W. B.
McRae, Eds., John Wiley, New York, 1973, pp. 51-61.
Theoretical models for chemistry.
- 90
-
R. J. Bartlett, C. E. Dykstra, and J. Paldus, in Advanced Theories and
Computational Approaches to the Electronic Structure of Molecules, C. E.
Dykstra, Ed., D. Reidel, Dordrecht, 1984, pp. 127-159.
Coupled-cluster methods for molecular calculations.
- 91
-
E. Merzbacher, Quantum Mechanics, 2nd ed., John Wiley and Sons, New York,
1970.
- 92
-
J. F. Stanton, 1996, unpublished notes, Austin, TX.
Fundamentals of second quantization.
- 93
-
W. Kutzelnigg, Mol. Phys., 94, 65 (1998).
Almost variational coupled cluster theory.
- 94
-
M. R. Hoffmann and J. Simons, J. Chem. Phys., 88, 993 (1988).
A unitary coupled-cluster method: Theory and applications.
- 95
-
M. R. Hoffmann and J. Simons, Chem. Phys. Lett., 142, 451 (1987).
Analytical energy gradients for a unitary coupled-cluster theory.
- 96
-
R. J. Bartlett and J. Noga, Chem. Phys. Lett., 150, 29 (1988).
The expectation value coupled-cluster method and analytical energy derivatives.
- 97
-
J. S. Arponen, Ann. Phys., 151, 311 (1983).
Variational principles and linked-cluster
expansions for static and
dynamic many-body problems.
- 98
-
R. F. Bishop and J. S. Arponen, Int. J. Quantum Chem. Symp., 24,
197 (1990).
Correlations in extended systems: A microscopic multilocal method for
describing both local and global properties.
- 99
-
R. J. Bartlett, S. A. Kucharski, J. Noga, J. D. Watts, and G. W. Trucks, in
Lecture Notes in Quantum Chemistry, Vol. 52 of Lecture Notes in
Chemistry, U. Kaldor, Ed., Springer-Verlag, Berlin, 1989, Chap. 6, pp. 125-149.
Some consideration of alternative ansätz in coupled-cluster theory.
- 100
-
P. G. Szalay, M. Nooijen, and R. J. Bartlett, J. Chem. Phys., 103,
281 (1995).
Alternative ansätze in single reference coupled-cluster theory. III. A
Critical analysis of different methods.
- 101
-
J. F. Stanton, 1998, unpublished notes, Austin, TX.
Coupled cluster theory for the ambidextrous.
- 102
-
H. Koch, H. J. Aa. Jensen, P. Jørgensen, and T. Helgaker, J. Chem.
Phys., 93, 3345 (1990).
Excitation energies from the coupled cluster singles and doubles linear
response function (CCSDLR). Applications to Be, CH+, CO, and H2O.
- 103
-
R. J. Rico and M. Head-Gordon, Chem. Phys. Lett., 213, 224
(1993).
Single-reference theories of molecular excited states with single and double
substitutions.
- 104
-
O. Christiansen, H. Koch, and P. Jørgensen, Chem. Phys. Lett., 243, 409 (1995).
The second-order approximate coupled cluster singles and doubles model CC2.
- 105
-
O. Christiansen, H. Koch, and P. Jørgensen, J. Chem. Phys., 103,
7429 (1995).
Response functions in the CC3 iterative triple excitation model.
- 106
-
H. Nakatsuji and K. Hirao, J. Chem. Phys., 68, 2053 (1978).
Cluster expansion of the wavefunction. Symmetry-adapted-cluster expansion, its
variational determination, and extension of open-shell orbital theory.
- 107
-
H. Nakatsuji, Chem. Phys. Lett., 59, 362 (1978).
Cluster expansion of the wavefunctions. Excited states.
- 108
-
H. Nakatsuji, Chem. Phys. Lett., 67, 329 (1979).
Cluster expansion of the the wavefunction. Electron correlations in ground and
excited states by SAC (symmetry-adapted-cluster) and SAC CI theories.
- 109
-
U. Kaldor, Theor. Chim. Acta, 80, 427 (1991).
The Fock space coupled cluster method: Theory and application.
- 110
-
D. Mukhopadhyay, S. Mukhopadhyay, R. Chaudhuri, and D. Mukherjee, Theor.
Chim. Acta, 80, 441 (1991).
Aspects of separability in the coupled cluster based direct method for energy
differences.
- 111
-
C. M. L. Rittby and R. J. Bartlett, Theor. Chim. Acta, 80, 469
(1991).
Multireference coupled cluster theory in Fock space.
- 112
-
J. F. Stanton, R. J. Bartlett, and C. M. L. Rittby, J. Chem. Phys., 97, 5560 (1992).
Fock space multireference coupled-cluster theory for general single determinant
reference functions.
- 113
-
M. Nooijen and R. J. Bartlett, J. Chem. Phys., 102, 3629 (1995).
Equation-of-motion coupled-cluster method for electron attachment.
- 114
-
M. Nooijen and R. J. Bartlett, J. Chem. Phys., 106, 6449 (1997).
Similarity transformed equation-of-motion coupled-cluster study of ionized,
electron attached, and excited states of free base porphyrin.
- 115
-
K. F. Freed, Annu. Rev. Phys. Chem., 22, 313 (1971).
Many-body theories of the electronic structure of atoms and molecules.
- 116
-
G. C. Wick, Phys. Rev., 80, 268 (1950).
The evaluation of the collision matrix.
- 117
-
J. Paldus and J. Cízek, Adv. Quantum Chem., 9, 105
(1975).
Time-independent diagrammatic approach to perturbation theory of fermion
systems.
- 118
-
T. D. Crawford, Ph.D. Thesis, University of Georgia, 1996.
Many-body perturbation theory and perturbational triple excitation corrections
to the coupled-cluster singles and doubles method for high-spin open-shell
systems.
- 119
-
R. J. Bartlett and D. M. Silver, Int. J. Quantum Chem. Symp., 9,
183 (1975).
Some aspects of diagrammatic perturbation theory.
- 120
-
R. J. Bartlett, 1994, unpublished notes, Gainesville, FL.
Systematic derivation of coupled-cluster equations.
- 121
-
E. R. Davidson, in The World of Quantum Chemistry, R. Daudel and B.
Pullman, Eds., D. Reidel, Dordrecht, 1974, pp. 17-30.
Configuration interaction description of electron correlation.
- 122
-
S. R. Langhoff and E. R. Davidson, Int. J. Quantum Chem., 8, 61
(1974).
Configuration interaction calculations on the nitrogen molecule.
- 123
-
R. J. Bartlett, I. Shavitt, and G. D. Purvis, J. Chem. Phys., 71,
281 (1979).
The quartic force field of H2O determined by many-body methods that include
quadruple excitation effects.
- 124
-
F. L. Pilar, Elementary Quantum Chemistry, 2nd ed., McGraw-Hill, New
York, 1990.
- 125
-
M. Urban, I. Cernusak, V. Kellö, and J. Noga, in Electron
Correlation in Atoms and Molecules, Vol. 1 of Methods in Computational
Chemistry, S. Wilson, Ed., Plenum, New York, 1987, Chap. 2, pp. 117-250.
Electron correlation in molecules.
- 126
-
C. Møller and M. S. Plesset, Phys. Rev., 46, 618 (1934).
Note on an approximation treatment for many-electron systems.
- 127
-
I. Hubac and P. Cársky, Phys. Rev., A22, 2392
(1980).
Correlation energy of open-shell systems. Application of the many-body
Rayleigh-Schrödinger perturbation theory in the restricted
Roothaan-Hartree-Fock formalism.
- 128
-
R. D. Amos, J. S. Andrews, N. C. Handy, and P. J. Knowles, Chem. Phys.
Lett., 185, 256 (1991).
Open-shell Møller-Plesset perturbation theory.
- 129
-
P. J. Knowles, J. S. Andrews, R. D. Amos, N. C. Handy, and J. A. Pople, Chem. Phys. Lett., 186, 130 (1991).
Restricted Møller-Plesset theory for open-shell molecules.
- 130
-
W. J. Lauderdale, J. F. Stanton, J. Gauss, J. D. Watts, and R. J. Bartlett,
Chem. Phys. Lett., 187, 21 (1991).
Many-body perturbation theory with a restricted open-shell Hartree-Fock
reference.
- 131
-
C. M. Murray and E. R. Davidson, Chem. Phys. Lett., 187, 451
(1991).
Perturbation theory for open-shell systems.
- 132
-
T. J. Lee and D. Jayatilaka, Chem. Phys. Lett., 201, 1 (1993).
An open-shell restricted Hartree-Fock perturbation theory based on symmetric
spin orbitals.
- 133
-
P. M. Kozlowski and E. R. Davidson, Chem. Phys. Lett., 226, 440
(1994).
Construction of open-shell perturbation theory invariant with respect to
orbital degeneracy.
- 134
-
T. D. Crawford, H. F. Schaefer, and T. J. Lee, J. Chem. Phys., 105,
1060 (1996).
On the energy invariance of open-shell perturbation theory with respect to
unitary transformations of molecular orbitals.
- 135
-
R. Krishnan and J. A. Pople, Int. J. Quantum Chem., 14, 91
(1978).
Approximate fourth-order perturbation theory of the electron correlation
energy.
- 136
-
R. Krishnan, M. J. Frisch, and J. A. Pople, J. Chem. Phys., 72,
4244 (1980).
Contribution of triple substitutions to the electron correlation energy in
fourth order perturbation theory.
- 137
-
J. R. Thomas, B. J. DeLeeuw, G. Vacek, and H. F. Schaefer, J. Chem.
Phys., 98, 1336 (1993).
A systematic study of the harmonic vibrational frequencies for polyatomic
molecules: The single, double, and perturbative triple excitation
coupled-cluster [CCSD(T)] method.
- 138
-
J. R. Thomas, B. J. DeLeeuw, G. Vacek, T. D. Crawford, Y. Yamaguchi, and H. F.
Schaefer, J. Chem. Phys., 99, 403 (1993).
The balance between theoretical method and basis set quality: A systematic
study of equilibrium geometries, dipole moments, harmonic vibrational
frequencies, and infrared intensities.
- 139
-
R. J. Bartlett and I. Shavitt, Chem. Phys. Lett., 50, 190 (1977).
Comparison of high-order many-body perturbation theory and configuration
interaction for H2O.
- 140
-
T. D. Crawford, J. F. Stanton, W. D. Allen, and H. F. Schaefer, J. Chem.
Phys., 107, 10626 (1997).
Hartree-Fock orbital instability envelopes in highly correlated
single-reference wavefunctions.
- 141
-
T. J. Lee, A. P. Rendell, and P. R. Taylor, J. Phys. Chem., 94,
5463 (1990).
Comparison of the quadratic configuration interaction and coupled-cluster
approaches to electron correlation including the effect of triple
excitations.
- 1
-
A. P. Rendell, T. J. Lee, and A. Komornicki, Chem. Phys. Lett., 178, 462 (1991).
A parallel vectorized implementation of triple excitations in CCSD(T):
Application to the binding energies of the AlH3, AlH2F, AlHF2, and
AlF3 dimers.
- 143
-
K. Raghavachari, J. A. Pople, E. S. Replogle, and M. Head-Gordon, J. Phys.
Chem., 94, 5579 (1990).
Fifth-order Møller-Plesset perturbation theory: Comparison of existing
correlation methods and implementation of new methods correct to fifth order.
- 144
-
A. L. L. East, Ph.D. Thesis, Stanford University, 1994.
Selected theoretical studies of vibrational anharmonicity and thermochemistry.
- 145
-
S. A. Kucharski and R. J. Bartlett, J. Chem. Phys., 108, 5243
(1998).
Noniterative energy corrections through fifth-order to the coupled cluster
singles and doubles method.
- 146
-
V. Kvasnicka, V. Lurinc, S. Biskupic, and M. Haring, Adv. Chem.
Phys., 52, 181 (1983).
Coupled-cluster approach in the electronic-structure theory of molecules.
- 147
-
S. A. Kucharski and R. J. Bartlett, Theor. Chim. Acta, 80, 387
(1991).
Recursive intermediate factorization and complete computational linearization
of the coupled-cluster single, double, triples, and quadruple excitation
equations.
- 148
-
C. L. Janssen, E. T. Seidl, G. E. Scuseria, T. P. Hamilton, Y. Yamaguchi, R. B.
Remington, Y. Xie, G. Vacek, C. D. Sherrill, T. D. Crawford, J. T. Fermann,
W. D. Allen, B. R. Brooks, G. B. Fitzgerald, D. J. Fox, J. F. Gaw, N. C.
Handy, W. D. Laidig, T. J. Lee, R. M. Pitzer, J. E. Rice, P. Saxe, A. C.
Scheiner, and H. F. Schaefer, PSI 2.0.8, PSITECH, Inc., Watkinsville, GA
30677, U. S. A., 1995. E-mail: psi@ccqc.uga.edu. This program is available
for a handling fee of $100.
- 149
-
MOLPRO is a package of ab initio programs written by H.-J. Werner and P. J.
Knowles with contributions from R. D. Amos, A. Berning, D. L. Cooper, M. J.
O. Deegan, A. J. Dobbyn, F. Eckert, C. Hampel, T. Leininger, R. Lindh, A. W.
Lloyd, W. Meyer, M. E. Mura, A. Nicklass, P. Palmieri, K. Peterson, R.
Pitzer, P. Pulay, G. Rauhut, M. Schütz, H. Stoll, A. J. Stone, and T.
Thorsteinsson. E-mail: molpro-support@tc.bham.ac.uk.
- 150
-
J. F. Stanton and J. Gauss and J. D. Watts and W. J. Lauderdale and R. J.
Bartlett, ACES II. The package also contains modified versions of the
MOLECULE Gaussian integral program of J. Almlöf and P. R. Taylor, the
ABACUS integral derivative program written by T. U. Helgaker, H. J. Aa.
Jensen, P. Jørgensen and P. R. Taylor, and the PROPS property evaluation
integral code of P. R. Taylor. E-mail: aces2@qtp.ufl.edu.
- 151
-
K. Dowd, High Performance Computing: RISC Architectures, Optimization, and
Benchmarks, O'Reilly and Associates, Sebastopol, California, 1993.
- 152
-
P. Cársky, L. J. Schaad, B. A. Hess, M. Urban, and J. Noga, J.
Chem. Phys., 87, 411 (1987).
Use of molecular symmetry in coupled-cluster theory.
- 153
-
M. Häser, J. Chem. Phys., 95, 8259 (1991).
Molecular point-group symmetry in electronic structure calculations.
- 154
-
F. Haase and R. Ahlrichs, J. Comput. Chem., 14, 907 (1993).
Semidirect MP2 gradient evaluation on workstation computers -- The MPGRAD
program.
- 155
-
M. Kollwitz, M. Häser, and J. Gauss, J. Chem. Phys., 108,
8295 (1998).
Non-Abelian point group symmetry in direct second-order many-body perturbation
theory calculations of NMR chemical shifts.
- 156
-
R. Pauncz, Spin Eigenfunctions: Construction and Use, Plenum, New York,
1979.
- 157
-
R. Pauncz, The Symmetric Group in Quantum Chemistry, CRC Press, Boca
Raton, FL, 1995.
- 158
-
X. Li and J. Paldus, J. Chem. Phys., 103, 6536 (1995).
Unitary group based open-shell coupled-cluster approach and triplet and
open-shell singlet stabilities of Hartree-Fock references.
- 159
-
S. Wilson, in Electron correlation in atoms and molecules, Vol. 1 of
Methods in Computational Chemistry, S. Wilson, Ed., Plenum Press, New
York, 1987, Chap. 3, pp. 251-309.
Four-index transformations.
- 160
-
C. Hampel, K. A. Peterson, and H.-J. Werner, Chem. Phys. Lett., 190, 1 (1992).
A comparison of the efficiency and accuracy of the quadratic configuration
interaction (QCISD), coupled-cluster (CCSD), and Brueckner coupled-cluster
(BCCD) methods.
- 161
-
P. R. Taylor, Int. J. Quantum Chem., 31, 521 (1987).
Integral processing in beyond-Hartree-Fock calculations.
- 162
-
M. J. Frisch, M. Head-Gordon, and J. A. Pople, Chem. Phys. Lett., 166, 281 (1990).
Semi-direct algorithms for the MP2 energy and gradient.
- 163
-
H. Koch, O. Christiansen, R. Kobayashi, P. Jørgensen, and T. Helgaker, Chem. Phys. Lett., 228, 233 (1994).
A direct atomic orbital driven implementation of the coupled cluster singles
and doubles (CCSD) model.
- 164
-
H. Koch, A. S. de Merás, T. Helgaker, and O. Christiansen, J. Chem.
Phys., 104, 4157 (1996).
The integrals-direct coupled-cluster singles and doubles model.
- 165
-
A. P. Rendell and T. J. Lee, J. Chem. Phys., 101, 400 (1994).
Coupled-cluster theory employing approximate integrals: An approach to avoid
the input/output and storage botlenecks.
- 166
-
J. M. L. Martin, J. Chem. Phys., 100, 8186 (1994).
On the performance of correlation consistent basis sets for the calculation of
total atomization energies, geometries and harmonic frequencies.
- 167
-
J. Paldus, New Horizons of Quantum Chemistry: Proceedings of the Fourth
International Congress of Quantum Chemistry, D. Reidel, Dordrecht, 1983,
pp. 31-60.
Coupled cluster approaches to many-electron correlation problem.
- 168
-
J. Paldus, in Methods in Computational Molecular Physics, S. Wilson and
G. H. F. Diercksen, Eds., Plenum, New York, 1992, pp. 99-194.
Coupled cluster theory.
- 169
-
A. Balkova and R. J. Bartlett, Chem. Phys. Lett., 193, 364
(1992).
Coupled-cluster method for open-shell singlets.
- 170
-
A. Balkova and R. J. Bartlett, J. Chem. Phys., 99, 7907 (1993).
The 2-determinant coupled-cluster method for electric properties of excited
electronic states: The lowest 1B1 and 3B1 states of the water
molecule.
- 171
-
D. Jayatilaka and T. J. Lee, Chem. Phys. Lett., 199, 211 (1992).
The form of spin orbitals for open-shell restricted Hartree-Fock reference
functions.
- 172
-
D. Jayatilaka and T. J. Lee, J. Chem. Phys., 98, 9734 (1993).
Open-shell coupled-cluster theory.
- 173
-
T. D. Crawford, T. J. Lee, and H. F. Schaefer, J. Chem. Phys., 107,
9980 (1997).
Spin-restricted Brueckner orbitals for coupled-cluster wavefunctions.
- 174
-
J. F. Stanton, J. Chem. Phys., 101, 371 (1994).
On the extent of spin contamination in open-shell coupled-cluster wave
functions.
- 175
-
T. J. Lee, A. P. Rendell, K. G. Dyall, and D. Jayatilaka, J. Chem. Phys.,
100, 7400 (1994).
Open-shell restricted Hartree-Fock perturbation theory: Some considerations
and comparisons.
- 176
-
S. Wolfram, Mathematica: A System for Doing Mathematics by Computer, 2nd
ed., Addison-Wesley, New York, 1991.
- 177
-
K. A. Brueckner, Phys. Rev., 96, 508 (1954).
Nuclear saturation and two-body forces. II. Tensor forces.
- 178
-
R. K. Nesbet, Phys. Rev., 109, 1632 (1958).
Brueckner's theory and the method of superposition of configurations.
- 179
-
R. A. Chiles and C. E. Dykstra, J. Chem. Phys., 74, 4544 (1981).
An electron pair operator approach to coupled-cluster wave functions.
Application to He2, Be2, and Mg2 and comparison with CEPA methods.
- 180
-
L. Z. Stolarczyk and H. J. Monkhorst, Int. J. Quantum Chem. Symp., 18, 267 (1984).
Coupled-cluster method with optimized reference state.
- 181
-
G. E. Scuseria and H. F. Schaefer, Chem. Phys. Lett., 142, 354
(1987).
The optimization of molecular orbitals for coupled cluster wavefunctions.
- 182
-
N. C. Handy, J. A. Pople, M. Head-Gordon, K. Raghavachari, and G. W. Trucks,
Chem. Phys. Lett., 164, 185 (1989).
Size-consistent Brueckner theory limited to double substitutions.
- 183
-
R. Kobayashi, N. C. Handy, R. D. Amos, G. W. Trucks, M. J. Frisch, and J. A.
Pople, J. Chem. Phys., 95, 6723 (1991).
Gradient theory applied to the Brueckner doubles method.
- 184
-
R. Kobayashi, R. D. Amos, and N. C. Handy, Chem. Phys. Lett., 184,
195 (1991).
The analytic gradient of the perturbative triple excitations correction to the
Brueckner doubles method.
- 185
-
T. J. Lee, R. Kobayashi, N. C. Handy, and R. D. Amos, J. Chem. Phys.,
96, 8931 (1992).
Comparison of the Brueckner and coupled-cluster approaches to electron
correlation.
- 186
-
J. F. Stanton, J. Gauss, and R. J. Bartlett, J. Chem. Phys., 97,
5554 (1992).
On the choice of orbitals for symmetry breaking problems with application to
NO3.
- 187
-
R. Kobayashi, H. Koch, P. Jørgensen, and T. J. Lee, Chem. Phys. Lett.,
211, 94 (1993).
Comparison of coupled-cluster and Brueckner coupled-cluster calculations of
molecular properties.
- 188
-
V. A. Kozlov and V. I. Pupyshev, Chem. Phys. Lett., 206, 151
(1993).
Self-consistent Brueckner theory for molecular orbitals.
- 189
-
R. Kobayashi, R. D. Amos, and N. C. Handy, J. Chem. Phys., 100,
1375 (1994).
Large basis set calculations using Brueckner theory.
- 190
-
J. D. Watts and R. J. Bartlett, Int. J. Quantum Chem. Symp., 28,
195 (1994).
Coupled-cluster singles, doubles, and triples calculations with Hartree-Fock
and Brueckner orbital reference determinants: A comparative study.
- 191
-
G. E. Scuseria, Int. J. Quantum Chem., 55, 165 (1995).
On the connections between Brueckner-coupled-cluster, density-dependent
Hartree-Fock, and density functional theory.
- 192
-
C. D. Sherrill, A. I. Krylov, E. F. C. Byrd, and M. Head-Gordon, J. Chem.
Phys., 109, 4171 (1998).
Energies and analytic gradients for a coupled-cluster doubles model using
variational Brueckner orbitals. Application to symmetry breaking in
O4+.
- 193
-
J. Cízek and J. Paldus, J. Chem. Phys., 47, 3976
(1967).
Stability conditions for the solutions of the Hartree-Fock equations for atomic
and molecular systems. Application to the pi-electron model of cyclic
polyenes.
- 194
-
J. Paldus and J. Cízek, Chem. Phys. Lett., 3, 1
(1969).
Stability conditions for the solutions of the Hartree-Fock equations for the
simple open-shell case.
- 195
-
E. R. Davidson and W. T. Borden, J. Phys. Chem., 87, 4783 (1983).
Symmetry breaking in polyatomic molecules: Real and artifactual.
- 196
-
W. D. Allen, D. A. Horner, R. L. DeKock, R. B. Remington, and H. F. Schaefer,
Chem. Phys., 133, 11 (1989).
The lithium superoxide radical: Symmetry breaking phenomena and potential
energy surfaces.
- 197
-
O. Goscinski, Int. J. Quantum Chem. Symp., 19, 51 (1986).
Are localized broken symmetry solutions acceptable in molecular calculations?
- 198
-
P. O. Löwdin, Rev. Mod. Phys., 35, 496 (1963).
Discussion on the Hartree-Fock Approximation.
- 199
-
K. Deguchi, K. Nishikawa, and S. Aono, J. Chem. Phys., 75, 4165
(1981).
Instabilities of the Hartree-Fock solution and the vibrational mode in a
molecule.
- 200
-
Y. Yamaguchi, I. L. Alberts, J. D. Goddard, and H. F. Schaefer, Chem.
Phys., 147, 309 (1990).
Use of the molecular orbital Hessian for self-consistent-field (SCF)
wavefunctions.
- 201
-
N. A. Burton, Y. Yamaguchi, I. L. Alberts, and H. F. Schaefer, J. Chem.
Phys., 95, 7466 (1991).
Interpretation of excited state Hartree-Fock analytic derivative anomalies for
NO2 and HCO2 using the molecular orbital Hessian.
- 202
-
L. A. Barnes and R. Lindh, Chem. Phys. Lett., 223, 207 (1994).
Symmetry breaking in O4+: An application of the Brueckner coupled-cluster
method.
- 203
-
Y. Xie, W. D. Allen, Y. Yamaguchi, and H. F. Schaefer, J. Chem. Phys.,
104, 7615 (1996).
Is the oxywater radical cation more stable then neutral oxywater?
- 204
-
J. Hrusák and S. Iwata, J. Chem. Phys., 106, 4877 (1997).
The vibrational spectrum of H2O2+ radical cation: An illustration of
symmetry breaking.
- 205
-
T. D. Crawford, J. F. Stanton, P. G. Szalay, and H. F. Schaefer, J. Chem.
Phys., 107, 2525 (1997).
The
excited state of NO2: Evidence for a Cs equilibrium structure and a failure of some spin-restricted reference
wavefunctions.
- 206
-
K. Shibuya, C. Terauchi, M. Sugawara, K. Aoki, K. Tsuji, and S. Tsuchiya, J. Mol. Struct., 413-414, 501 (1997).
Vibrational level structure of NO2
in the energy region
of 16200-21000 cm-1: Evidence for the breakdown of C2v symmetry.
- 207
-
R. A. King, T. D. Crawford, J. F. Stanton, and H. F. Schaefer, to be published.
More bad news for perturbation theory and density-functional theory.
- 208
-
P. Pulay, Chem. Phys. Lett., 100, 151 (1983).
Localizability of dynamic electron correlation.
- 209
-
S. Sæbø and P. Pulay, Chem. Phys. Lett., 113, 13 (1985).
Local configuration interaction: An efficient approach for larger molecules.
- 210
-
P. Pulay and S. Sæbø, Theor. Chim. Acta, 69, 357 (1986).
Orbital-invariant formulation and second-order gradient evaluation in
Møller-Plesset perturbation theory.
- 211
-
S. Sæbø and P. Pulay, J. Chem. Phys., 86, 914 (1987).
Fourth-order Møller-Plesset perturbation theory in the local correlation
treatment. I. Method.
- 212
-
S. Sæbø, W. Tong, and P. Pulay, J. Chem. Phys., 98, 2170
(1993).
Efficient elimination of basis set superposition errors by the local
correlation method: Accurate ab initio studies of the water dimer.
- 213
-
C. Hampel and H.-J. Werner, J. Chem. Phys., 104, 6286 (1996).
Local treatment of electron correlation in coupled cluster theory.
- 214
-
J. D. Watts and R. J. Bartlett, J. Chem. Phys., 101, 3073 (1994).
The inclusion of connected triples excitations in the equation-of-motion
coupled-cluster methods.
- 215
-
J. D. Watts and R. J. Bartlett, Chem. Phys. Lett., 233, 81
(1995).
Economical triple excitation equation-of-motion coupled-cluster methods for
excitation-energies.
- 216
-
J. D. Watts and R. J. Bartlett, Chem. Phys. Lett., 258, 581
(1996).
Iterative and noniterative triple excitation corrections in coupled-cluster
methods for excited electronic states -- The EOM-CCSDT-3 and
EOM-CCSD(
)
methods.
- 217
-
O. Christiansen, H. Koch, and P. Jørgensen, J. Chem. Phys., 105,
1451 (1996).
Perturbative triple excitation corrections to coupled cluster singles and
doubles excitation energies.
- 218
-
P. Piecuch, N. Oliphant, and L. Adamowicz, J. Chem. Phys., 99,
1875 (1993).
A state-selective multireference coupled-cluster theory employing the
single-reference formalism.
- 219
-
P. Piecuch and L. Adamowicz, J. Chem. Phys., 102, 898 (1995).
Breaking bonds with the state-selective multireference coupled-cluster methods
employing the single-reference formalism.
- 220
-
A. Banerjee and J. Simons, J. Chem. Phys., 76, 4548 (1982).
Applications of multiconfigurational coupled-cluster theory.
- 221
-
W. D. Laidig and R. J. Bartlett, Chem. Phys. Lett., 104, 424
(1984).
A multi-reference coupled-cluster method for molecular applications.
- 222
-
P. G. Szalay and R. J. Bartlett, J. Chem. Phys., 103, 3600
(1995).
Approximately extensive modifications of the multireference configuration
interaction method: A theoretical and practical analysis.
- 223
-
K. B. Ghose, P. Piecuch, and L. Adamovicz, J. Chem. Phys., 103,
9331 (1995).
Improved computational strategy for the state-selective coupled-cluster theory
with semi-internal triexcited clusters: Potential energy surface of the HF
molecule.
- 224
-
J. T. Fermann, C. D. Sherrill, T. D. Crawford, and H. F. Schaefer, J.
Chem. Phys., 100, 8132 (1994).
Benchmark studies of electron correlation in six-electron systems.
- 225
-
N. C. Handy and A. M. Lee, Chem. Phys. Lett., 252, 425 (1996).
The adiabatic approximation.
- 226
-
J. Almlöf and P. R. Taylor, J. Chem. Phys., 86, 4070 (1987).
General contraction of Gaussian basis sets. I. Atomic natural orbitals for
first- and second-row atoms.
- 227
-
J. Almlöf, T. Helgaker, and P. R. Taylor, J. Phys. Chem., 92,
3029 (1988).
Gaussian basis sets for high-quality ab initio calculations.
- 228
-
T. H. Dunning, J. Chem. Phys., 90, 1007 (1989).
Gaussian basis sets for use in correlated molecular calculations. I. The atoms
boron through neon.
- 229
-
B. J. Persson and P. R. Taylor, J. Chem. Phys., 105, 5915 (1996).
Accurate quantum-chemical calculations: The use of Gaussian-type geminal
functions in the treatment of electron correlation.
- 230
-
J. M. L. Martin and P. R. Taylor, J. Chem. Phys., 106, 8620
(1997).
Benchmark quality total atomization energies of small polyatomic molecules.
- 231
-
T. Helgaker, W. Klopper, H. Koch, and J. Noga, J. Chem. Phys., 106,
9639 (1997).
Basis-set convergence of correlated calculations on water.
- 232
-
W. Klopper, 1996, Habilitationsschrift, Eidgenössischen Technischen
Hochschule Zürich.
r12-dependent wave functions.
T. Daniel Crawford / crawdad@ccqc.uga.edu
23 November 1998