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tumitumi123

Member

Registered: 2017-06-13

Posts: 16

How to understand basis set file?

Dear all
In my Br2 calculation, I use ano-rcc-vdzp basis set, which is double zeta polarized. In the output it give me:
Basis set label:BR.ANO-RCC...4S4P2D.
This is consistent with the "molcas help basis br":

 Recommended basis sets for  BR 
Br.DEF-SV(P)                             Br.SVP....
Br.DEF-SVP                               Br.SVP....
Br.ANO-S-MB                              Br.ANO-S...4s3p1d.
Br.ANO-S-VDZ                             Br.ANO-S...5s4p1d.
Br.ANO-S-VDZP                            Br.ANO-S...4s4p2d.
Br.ANO-S-VTZP                            Br.ANO-S...6s5p3d.
Br.ANO-RCC-MB                            Br.ANO-RCC...4s3p1d.
Br.ANO-RCC-VDZ                           Br.ANO-RCC...5s4p1d.
Br.ANO-RCC-VDZP                          Br.ANO-RCC...4s4p2d.
Br.ANO-RCC-VTZ                           Br.ANO-RCC...6s5p3d.
Br.ANO-RCC-VTZP                          Br.ANO-RCC...6s5p3d1f.
Br.ANO-RCC-VQZP                          Br.ANO-RCC...7s6p4d2f1g.

Then I check the ano-rcc file, in the comment it said:

* Contraction range: 4s3p1d - 9s8p6d4f2g                               *
* Results(eV)                                                          *
* Contraction           CASPT2(Br,2P)      IP      EA                  *
* MB: 4s3p1d           -2604.2998243567  11.78    1.305 	       *
* DZP:5s4p2d1f         -2604.4287252874  11.50    3.068 	       *
* TZP:6s5p3d2f1g       -2604.4565755543  11.60    3.327 	       *
* QZP:7s6p4d3f2g       -2604.4616557137  11.62    3.364 	       *
* large:9s8p6d4f2g     -2604.4631195288  11.62    3.367 	       *
* Primitive:           -2604.4631793686  11.60    3.367 	       *
* Expt.(averaged over J)                 11.87    3.516 	       *

Here the DZP is 5s4p2d1f , is this the basis set how they do calculation? It is not the description for ano-rcc-vdzp?

If I use ano-rcc-vdzp, there are 4s, does this mean I can only choose the first four column in the contraction matrix? If 7s, I choose first 7 column?
And what is the meaning of the additional 2 line after the contraction matrix(for example, 1 and -3.1588, see below), I did not see any explain in the manual. Below is part of the basis file.

*  d-type ANO's, max 6 functions can be used
   11    6
560.732930 238.734218 104.773142 45.0684265 20.6137781
9.44445062 4.25252005 1.87261996 0.74603755 0.29841502
0.11936601
  0.00068865 -0.00019069  0.00023435 -0.00061670  0.00151526 -0.00355242
  0.00240467 -0.00072866  0.00066522  0.00117643 -0.00473504  0.02039093
  0.01433129 -0.00402111  0.00471564 -0.01002897  0.02283013 -0.05178080
  0.05438352 -0.01604723  0.01608428  0.00264092 -0.03494286  0.22138555
  0.15304298 -0.04356888  0.04999276 -0.09423083  0.21145080 -0.33936634
  0.30550848 -0.09341332  0.10215584  0.00182149 -0.13003377  2.09520411
  0.38567672 -0.10869852  0.14963391 -0.45628375  1.26690250 -3.07852134
  0.29219340 -0.09679023  0.14147927  0.44552409 -2.56827956  2.04709473
  0.08714805  0.37268129 -1.06541591  0.86804683  2.33992505 -1.01273270
 -0.00020028  0.62422320  0.35047390 -1.76389944 -1.56826608  0.50604736
  0.00134169  0.15811311  0.68066714  1.28810784  0.69379834 -0.18265878
  1
     -3.1588
*  f-type ANO's, max 4 functions can be used
    4    4
1.417310 0.566924 0.226769 0.090707
  0.09298547 -0.33695994  1.10050397 -0.80726497
  0.68169570 -0.69024865 -0.97941384  1.31083202
  0.34586395  1.03430998  0.08367240 -1.55635355
  0.02206141  0.07354479  0.60777241  1.26872782
  0

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: How to understand basis set file?

I don't know if it makes any sense that a VDZ contraction has 5s and a VDZP has 4s (and it's missing the f functions), this looks like a bug to me and it seems all Ga-Kr ANO bases have the same. The contractions are defined in the
basis_library/basis.tbl file, which is read both by seward and "molcas help", so they should agree.

With ANO-type basis sets, you can choose whatever contraction you like specifying the number of s, p, d... functions, and they are indeed taken from the first columns in the contraction matrix. The "MB", "VDZP", etc. labels are simply shortcuts intended to make life easier.

I think the extra lines are the atomic orbital energies, which can be used to generate initial guess orbitals.