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Re^4: What does the "d5=1" option do?

Vyacheslav
kreme_vg@chemy.kolasc.net.ru

Hi!
It is the greatest surprise for me for last one and a half year (it is my quantum-chemical experience)... I saw in books relation between cartesian and spherical bases for d-functions, but I didn't suspect, that energies in different bases are different!
OK, then i do not understand why in outputs of runs with "d5=1" i have six d-AO, instead of five?! And one more question: why energies (with and without "d5=1") are equal for K+?
P.S. It is a pity that on page related to this option (http://classic.chem.msu.su/gran/gamess/spherical.html) there is no warning of this stunning fact…

P.P.S. Theoretical group analysis is always based on existence of five d-AO (in books for chemists). The spectral data too specify existence of five d-AO. Where to extract energy of these five AO?

P.P.S. Please, excuse me for verbosity...  Just I've looked two my calculations: optimization of a complex 6Na*Nb(5)Cl6 with and without "d5=1" option. In the first case calculation converges, and in the second - 6th cation goes away, i.e. the complex keeps 6 cations in the first case, and isn't in the second case. This is fundamental difference. What calculation is preferable? Basic sets are identical in both calculations.
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On Sun Nov 1 '09 10:23pm, Alex Granovsky wrote
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>Hi,

>The reason is very simple - cartesian basis contains
>more functions than the pure spherical one.

>E.g. any cartesian d-shell has six basis functions.
>There are five linear combinations of them that
>indeed transforms according to D irrep, while the last one is of S type
>(namely, the dx2+dy2+dz2 one). The latter is exactly what is called
>spherical contaminant and is removed or project out if one deals
>with pure spherical basis sets.

>regards,
>Alex Granovsky

[ This message was edited on Mon Nov 2 '09 at 5:58pm by the author ]

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