[molpro-user] basis keywords in CCSD(T)-F12

[Changjian Xie]

Dear All:
I encountered a problem with the basis keywords 'VQZ-F12' and
'CC-PVQZ-F12', which can produce a small energy difference in CCSD(T)-F12
calculations. For example, an input is:

*geomtype=xyz*
*  geometry={*
* 1*
* atom Cl*
*  Cl   0.0 0.0 0.0*
* }*

* basis=VQZ-F12*
* hf;*
* uccsd(t)-F12*

the energy in output is :

    UCCSD(T)-F12        HF-SCF
   -459.70434359   -459.48381187

If the input is:

 * geomtype=xyz*
*  geometry={*
* 1*
* atom Cl*
*  Cl   0.0 0.0 0.0*
* }*

* basis=CC-PVQZ-F12*
* hf;*
* uccsd(t)-F12*

then the energy is :
    UCCSD(T)-F12        HF-SCF
   -459.70434457   -459.48381187

So, the difference for 'VQZ-F12' and 'CC-PVQZ-F12' is 0.00000098 a.u.
(0.215 cm-1). Actually 'VQZ-F12' is just the abbreviation for
'CC-PVQZ-F12', but I found the difference in output files is

<  *Basis set CC-PVQZ/JKFIT generated.      Number of basis functions:
148*         *------- in 'VQZ-F12' output*
---
>  *Basis set AUG-CC-PVQZ/JKFIT generated.  Number of basis functions:
184*      *------- in 'CC-PVQZ-F12' output*

So the difference basis sets are generated for 'VQZ-F12' and 'CC-PVQZ-F12',
does this make sense or something incorrect in my input files?

Thanks in advance!

Best regards,
Changjian Xie
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