Page 63 - Valence Bond Methods. Theory and Applications

2H 2 and localized orbitalØ
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These functions contribute over 99% of the total wave function ið both cases. The
smaller value for the larger basis reflects the larger number of small contribution
basis functions ið that case. Although the fairly large number of basis functions
that contribute with only minor weights hŁve an important impact on lowering the
energy, the large weight of the ccvalent function indicates that the bond ið the H 2
molecule is just as chemists always describe it: a ccvalent bond.