

Dear Miquel,
instaed of discussing the Laplacian, it is better to compare the 
energy-density at the bond kritical point (This is the negative K-Value 
in the Bader-output).
For references see:
D. Cremer, E. Kraka, Angew. Chem. 8, 614 (1984) (german edition)
G. Frenking, D. Cremer, Stucture and Bonding 73, Springer Verlag, 
Berlin-Heidelberg (1990)
W. Koch, G. Frenking, J. Gauss, D. Cremer, J. R. Collins, J. Am. Chem. 
Soc. 109 5919 (1987).
I hope this helps, with best regards, 
Andreas Ehlers

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= Andreas Ehlers    - Afdeling Theoretische Chemie, Faculteit Scheikunde  =
=                   - Vrije Universiteit Amsterdam                        =
=                   - De Boelelaan 1083, 1081 HV Amsterdam                =
=                   - [ [email-masked]                          =
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