CCL:G: NBO and GAUSSIAN

In the NBO analysis the principal quantum numbers for the NAO's are assigned on the basis of the energy order in the HF matrix, or according to their occupancy. When this order doesnt coincide then the warning message warning "population inversion" appears. In other words there are some NBOs with higher occupancies than others that are lower in energy, as would be expected by regular theory. According to tutorials by Weinhold himself (available at http://www.chem.wisc.edu/~nbo5/ ) this isnt that much a problem.

I hope I was helpful

"Aggelos Avramopoulos aggavramop{=}yahoo.gr" <owner-chemistry()ccl.net> escribió:

I made a calculation of the natural population analysis of a system

by using the NBO program employed in GAUSSIAN 98. However,

in the output file, just before the printing of the Summary of the Pop.

analysis the following warning was appeared:

WARNING: Population inversion found on atom Xe 1
           Population inversion found on atom H 2
           Population inversion found on atom C 3
           Population inversion found on atom C 4
           Population inversion found on atom Xe 5
           Population inversion found on atom C 6
           Population inversion found on atom C 7
           Population inversion found on atom Xe 8
           Population inversion found on atom H 9

                                     Natural Population
               Natural   -----------------------------------------------
    Atom No    Charge        Core      Valence    Rydberg      Total
-----------------------------------------------------------------------
     Xe 1    0.78167     45.99924     7.15753    0.06157    53.21833
      H 2   -0.09591      0.00000     1.08564    0.01027     1.09591
      C 3   -0.58778      1.99822     4.53350    0.05606     6.58778
      C 4   -0.59076      1.99809     4.54330    0.04937     6.59076
     Xe 5    0.98590     45.99876     6.93525    0.08009    53.01410
      C 6   -0.59075      1.99809     4.54327    0.04938     6.59075
      C 7   -0.58794      1.99822     4.53365    0.05606     6.58794
     Xe 8    0.78167     45.99924     7.15749    0.06160    53.21833
      H 9   -0.09610      0.00000     1.08583    0.01027     1.09610
=======================================================================
   * Total * 0.00000    145.98988    41.57546    0.43466   188.00000

Is there anyone who knows how to interpret this warning?

Thanks in advance for every comment

Aggelos Avramopoulos

×ñçóéìïðïéåßôå Yahoo!
ÂáñåèÞêáôå ôá åíï÷ëçôéêÜ ìçíý ìáôá (spam); Ôï Yahoo! Mail äéáèÝôåé ôçí êáëýôåñç äõíáôÞ ðñïóôáóßá êáôÜ ôùí åíï÷ëçôéêþí ìçíõìÜôùí
http://login.yahoo.com/config/mail?.intl=gr