[molpro-user] Diffrerence between molpro and mrcc fci

[Peter Knowles]

I think if you were to use the cc-pVDZ basis set that is referred to in https://link.springer.com/article/10.1007%2Fs00214-010-0764-0 , i.e. with a d exponent of 0.1144 rather than the 0.1239 served up by https://bse.pnl.gov/bse/portal and inside MRCC, you would be able to obtain -7.43263693 with 
any reputable FCI program.

Peter
 
> On 25 May 2017, at 20:44, Cong Wang <cwang at chem.helsinki.fi> wrote:
> 
> Excuse me, the link for the question on mrcc forum is
> 
> http://www.mrcc.hu/index.php/forum/running-mrcc/81-difference-between-molpro-and-mrcc-fci#376
> 
> I am sorry for this inconvenience
> 
> 
> 
> 2017-05-25 15:43 GMT-04:00 Cong Wang <cwang at chem.helsinki.fi>:
> Hi everyone,
> 
>   I tried to compare molpro and mrcc full-ci/cc-pVDZ for a lithium atom and posted my question on mrcc forum.
> 
> The molpro convergence pattern is
> 
>   1   1    0.6  1.00000000    -7.43241988
>                                            0.03 -0.00020840 -0.00020768
>   2   1    0.6  0.00860636    -7.43263477
>                                            0.05 -0.00000213 -0.00000210
>   3   1    0.6  0.00085487    -7.43263690
>                                            0.09 -0.00000004 -0.00000003
>   4   1    0.6  0.00009565    -7.43263693
>                                            0.11 -0.00000000 -0.00000000
>   5   1    0.6  0.00001648    -7.43263693
>                                            0.10 -0.00000000 -0.00000000
>   6   1    0.6  0.00000299    -7.43263693
>                                            0.12 -0.00000000 -0.00000000
>   7   1    0.6  0.00000052    -7.43263693
>                                            0.11 -0.00000000 -0.00000000
>   8   1    0.6  0.00000010    -7.43263693
> 
> mrcc is 
>  
>  Iteration  8  CI energy:    -7.43263751  Energy decrease:   0.0000E+00
>  ======================================================================
>  Norm of residual vector:     1.0477E-12      Convergence:   5.1862E-12
>  CPU time [min]:     0.012                   Wall time [min]:     0.002
>  
>  Iteration  9  CI energy:    -7.43263751  Energy decrease:   0.0000E+00
>  ======================================================================
>  Norm of residual vector:     4.7386E-14      Convergence:   2.1137E-13
>  CPU time [min]:     0.013                   Wall time [min]:     0.002
>  
>  Iteration 10  CI energy:    -7.43263751  Energy decrease:   0.0000E+00
>  ======================================================================
>  Norm of residual vector:     1.8060E-15      Convergence:   1.2633E-14
>  CPU time [min]:     0.014                   Wall time [min]:     0.002
>  
>  Iteration 11  CI energy:    -7.43263751  Energy decrease:   0.0000E+00
> 
> 
> Though I was suggested to tighten molpro convergence threshold, my input:  
> {fci;thr,1d-16;core,0}
> and convergence pattern seems unable to reach mrcc value. Hence, I would like to ask in this mailing list, what is the actual reason for this discrepancy? i.e. 
>   -7.43263693
>   -7.43263751 
> 
> Thank you
> 
> 
> 
> _______________________________________________
> Molpro-user mailing list
> Molpro-user at molpro.net
> http://www.molpro.net/mailman/listinfo/molpro-user

--
Prof. Peter J. Knowles             
School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
Telephone: +44 29 208 79182
Email: KnowlesPJ at Cardiff.ac.uk 

Yr Athro Peter J. Knowles
Yr Ysgol Cemeg, Prifysgol Caerdydd,
Prif Adeilad, Plas y Parc
Caerdydd CF10 3AT, DU
Ffôn: +44 2920 879182
Ebost: KnowlesPJ at Caerdydd.ac.uk
Ysgrifennwch ataf yn Gymraeg neu Saesneg