[molpro-user] Spin-Orbit /basis set problem?

[Evans, Dr C.J.]

Hi All,

I have been trying to do Spin-Orbit calculations on GeCH, GeCF and GeCCl and have found that GeCF will not converge at the MCSCF(MULTI) step but GeCH and GeCCl will.

In each case I put the basis as (e.g. GeCF):

Basis={
spdf,Ge,cc-pVTZ
spdf,C,cc-pVTZ
spdf,F,cc-pVTZ
}

For GeCF this never converges during the MCSCF step. It also doesn't converge when I use

Basis={
spd,Ge,cc-pVTZ
spd,C,cc-pVTZ
spd,F,cc-pVTZ
}

However, it does converge when I use:

Basis={
spd,Ge,cc-pVDZ
spd,C,cc-pVDZ
spd,F,cc-pVDZ
}

Could it be a problem with the F cc-pVTZ basis set since I have no problems with GeCH, GeCCl, or GeCBr?

I have got around the problem by first doing a RHF calculation using:

Basis={
Ge,cc-pVTZ
C,cc-pVTZ
F,cc-pVTZ
}

then I redo the RHF calculation using:

Basis={
spdf,Ge,cc-pVTZ
spdf,C,cc-pVTZ
spdf,F,cc-pVTZ
}

before doing the MULTI step however, will this affect my SO results in anyway?

Cheers

Corey

Dr Corey Evans
Department of Chemistry
University of Leicester
Leicester, LE1 7RH, UK

phone (office): +44 (0)116 252 3985 
Fax.          : +44 (0)116 252 3789