The interacting correlated fragments model for weak interactions, basis set superposition error, and the helium dimer potential
We report the LM-2 helium dimer interaction potential, from helium separations of 1.6 A to dissociation, obtained by careful convergence studies with respect to configuration space, through a sequence of interacting correlated fragment (ICF) wave functions, and with respect to the primitive Slater-type basis used for orbital expansion. Parameters of the LM-2 potential are /ital r//sub /ital e//=2.969 A, /ital r//sub /ital m//=2.642 A, and /ital D//sub /ital e//=10.94 K, in near complete agreement with those of the best experimental potential of Aziz, McCourt, and Wong (Mol. Phys. /bold 61/, 1487 (1987)), which are /ital r//sub /ital e//=2.963 A, /ital r//sub /ital m//=2.637 A, and /ital D//sub /ital e//=10.95 K. The computationally estimated accuracy of each point on the potential is given; at /ital r//sub /ital e// it is 0.03 K. Extrapolation procedures used to produce the LM-2 potential make use of the orbital basis inconsistency (OBI) and configuration base inconsistency (CBI) adjustments to separated fragment energies when computing the interaction energy. These components of basis set superposition error (BSSE) are given a full discussion.
- Research Organization:
- IBM Almaden Research Center, San Jose, California 95120-6099(US)
- OSTI ID:
- 5961903
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 91:4
- Country of Publication:
- United States
- Language:
- English
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