[molpro-user] BSSE with ECP potential/basis

[Amit Sharma]

Thanks!

On Sat, May 7, 2016 at 10:53 AM, Kirk Peterson <kipeters at wsu.edu> wrote:

> Hi Amit,
>
> as far as I know, one doesn’t have to treat ECP-based calculations any
> differently compared to those without.  It is a little surprising  you get
> the same CP corrected binding energies with these two basis sets, but DZ
> results can be strange sometimes.
>
> regards,
>
> -Kirk
>
>
> On May 6, 2016, at 5:21 AM, Amit Sharma <greifsw at gmail.com> wrote:
>
> Hi all,
> I want to calculate BSSE where one of the atoms has an ECP potential basis
> on it. Should BSSE be computed differently for ECP? There is some
> discussion in the literature about switching off the core but I am not sure
> how to do that in molpro.
>
> As a test I compute BSSE for two noble gas atoms with AVDZ basis and get a
> BSSE of about 47 cm-1. Then I switch the basis on one of the atoms to be
> def2-SVPD and I get BSSE which is twice that of the AVDZ result (about 97
> cm-1).
>
> However, the CP corrected interaction energy is approximately the same
> between the two calculations. 400 cm-1 vs 403 cm-1, so maybe nothing
> special needs to be done. Can anyone please help clarify this for me.
> Thanks
> Amit
>
> ***, Ar + he bsse
>
> geometry={Ar
> He Ar Rx}
>
> Rx=5.0
>
> !basis=avdz,he=avdz
> basis=def2-SVPD,he=avdz
>
>
>  text,calculation for complex
>  hf                            !RHF for total system
>  ccsd(t)
>  e_Arhe=energy                 !save energy in variable e_Arhe
>
>  text,cp calculation for HE
>  dummy,Ar                      !make Ar a dummy
>  hf                           !RHF for He
>  ccsd(t)
>  e_he=energy                   !save energy in variable e_he
>
>  text,cp calculation for Ar
>  dummy,he                      !make he dummy
>  hf
>  ccsd(t)
>  e_Ar=energy                   !save energy in variable e_Ar
>
>  text,separate calculation for he
>  symmetry,x,y
>  geometry={he}                 !geometry for he alone
>  hf                            !RHF for He
>  ccsd(t)
>  e_he_inf=energy               !save energy in variable e_he_inf
>
>  text,separate calculation for Ar
>  symmetry,x,y
>  geometry={Ar}                 !geometry for Ar alone
>  hf                            !scf for Ar
>  ccsd(t)
>  e_Ar_inf=energy               !save energy in variable e_Ar_inf
>
> de(i)=(e_Arhe-e_he_inf-e_Ar_inf)*tocm    !compute uncorrected interaction
> energy
> de_cp(i)=(e_Arhe-e_he-e_Ar)*tocm         !compute counter-poise corrected
> interaction energy
> bsse_he(i)=(e_he-e_he_inf)*tocm          !BSSE for he
> bsse_Ar(i)=(e_Ar-e_Ar_inf)*tocm          !BSSE for Ar
>
> bsse_tot(i)=bsse_he(i)+bsse_Ar(i)              !total BSSE
> _______________________________________________
> Molpro-user mailing list
> Molpro-user at molpro.net
>
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.molpro.net_mailman_listinfo_molpro-2Duser&d=CwICAg&c=C3yme8gMkxg_ihJNXS06ZyWk4EJm8LdrrvxQb-Je7sw&r=mqaXWsZ0ghQR-pXvPLjY_g&m=B4tbS47XX15ILr4ZVAykT-Xbolq5pVnAkv_J6VroMFA&s=F11UmXf2GReqdN-sR8iHnnhZnWxhUD-cTwkh4cU8yJo&e=
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.molpro.net/pipermail/molpro-user/attachments/20160507/11f00e61/attachment-0001.html>