[molpro-user] Li+ MP2 problem

[Grant Hill]

For Li with MP2 (and other single reference post-HF methods) the default is that the 1s electrons are included in the frozen core approximation. This means that for Li+ there are no electrons to be correlated and hence the error that is output.

Two courses of action spring to mind:

1) Use a larger system for your tests.

2) Remove the frozen core approximation for this system (consult the manual on how to do this), note your basis set may not be appropriate for doing this.

HTH,

Grant

On 1 Jan 2010, at 01:12, AYORINDE HASSAN wrote:

> Hi all,
> I am a new molpro user. I was trying to run an mp2 energy calculation of Li cation(Li+) as a test, but I always encounter an error which is absent when i run hartree fock or dft. The error is as follows:
> GLOBAL ERROR fehler on processor   2                                         
> 
> GLOBAL ERROR fehler on processor   0                                         
> 
> 1PROGRAM * MP2 (Closed-shell)     Authors: C. Hampel, H.-J. Werner, 1991, M. Deegan, P.J. Knowles, 1992,  U. Schumann, 2001
> 
> 
> The number of valence orbitals is .le. 0.
> One possible cause of this is that there are no orbitals available, ie you might have forgotten
> to do a Hartree-Fock calculation. Another possiblity is that the number of electrons is .le. half
> the number of uncorrelated core orbitals.
> 
> The inout file is as follows:
> ***,Lithium
> memory,200,m
> geomtyp=xyz
> geometry={
> 1
> Geometry specification:
> Li,	0.,	0.,	0.
> }
> basis={
> ! LITHIUM       (10s,6p,4d) -> [5s,3p,2d]
> ! LITHIUM       (10s,6p,4d) -> [5s,3p,2d]
> s, LI , 1359.4466000, 204.0264700, 46.5495410, 13.2325940, 4.2861480, 1.4955420, 0.5422380, 0.0739680, 0.0280950, 0.0106710
> c, 1.5, 0.0008440, 0.0064860, 0.0324770, 0.1174200, 0.2945800
> c, 6.7, 0.4495150, 0.5422380
> c, 8.8, 1.0000000
> c, 9.9, 1.0000000
> c, 10.10, 1.0000000
> p, LI , 4.1700000, 1.1725600, 0.3292700, 0.0927100, 0.0260700, 0.0073310
> c, 1.4, 0.0051120, 0.0209070, 0.0916720, 0.4492600
> c, 5.5, 1.0000000
> c, 6.6, 1.0000000
> d, LI , 0.3292700, 0.0927100, 0.0260700, 0.0073310
> c, 1.2, 0.1597570, 1.4754840
> c, 3.4, 0.3705780, 0.0178470
> }
> {hf;wf,2,1,0}
> mp2
> 
> Can someone kindly tell me why I am encountering this error at the MP2 level? I am missing something in my input file?
> 
> 
> 
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