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! 0 1, 2 `[ HF 0 H2O d799ìíîïð{ñ)ò`oQFull-CI 09ËÌ116-31G YZfu-§# bra 0 valence Ã¤9 CI stfu-§QHF p[ CISD,H2O p[ CISDTQ -§@69~.&;70 3 67~.-QM`a[Deviation from FCI (mH)

Deviation from FCI (mH)ˆ SD ' Sˆ SD 097t8ë`}rQ2,`3hËÌ-ú-120vp¯(F-H bond length (Å)

O-H bond length / Re

Figure 1: Deviations from Full-CI energy. Potentialenergies of HF dissociation.

Figure 2: Deviations from Full-CI energy.
Potential energies of H2O double dissociation.

÷Q[\` CO 9

Table Dissociation of CO molecule. Deviation from Full-CI energy in Hartree. Total energies calculated by RHF andFull CI are included. 6-31G basis sets were used. 1s orbitals were kept frozen.

`o11MRbraSACSD

Methods

97t8ë[`3ËÌ
v+@12vQCRCCSD(T)L, CCSD(2)T ,`}2W0]^120N_kv.¯k0vd2

RHF
Full-CI
CCSD
CCSD(T)
CCSD(2)TCRCCSD(T)CRCCSD(T)LMRbraSACSD+ptT(iter.)+ptT(non-iter.)SD+ptT(non-iter.)+(1.00-112.610824-112.805981
0.006527
0.000915
0.001282
0.001879-0.000173
0.004686
0.002803
0.003216-0.000272

1.25-112.640643-112.878130
0.013379
0.001571
0.001823
0.004164-0.001302
0.007447
0.003077
0.004232-0.001357

C-O bond length / Å
1.50-112.510921-112.794173
0.025498
0.002619
0.001588
0.009037-0.003925
0.0111210.004209
0.006148-0.000361

2.00-112.316829-112.643365
0.033619-0.068335-0.000748-0.012976-0.014218
0.026556
0.0131250.017972
0.014345

2.50-112.268294-112.578024
0.150472
0.143573
0.144984
0.1451200.142547
0.031211
0.016599
0.018330
0.016337

References[1] I. I. Ukrainskii, Theor. Math. Phys., 32, 816 (1978). [2] T. Van Voorhis, M. Head-Gordon, J. Chem. Phys. 113 (2000)
8873. [3]J. Hasegawa, H. Nakatsuji, Chem. Lett. 34 (2005) 1356. [4]LMNOPQd7`amb 2009, 4P135.