[molpro-user] Double minima problem of CaF ground state with MRCI

[侯世林]

Dear Molpro users,

I am calculating the CaF ground state with MRCI/cc-pvxz (x=T,Q,5), and find there are two minima on its potential curve: one at Re(~2.0 angstrom), another at R=(2.5~2.6 angstrom). Active spaces are set from the default to {8,3,3} for nine active electrons.

I also try the ACPF approach; the results are similar to those of MRCI. Attached are the results and input file of ACPF/cc-pcvqz. Note with the ACPF/cc-pcv5z the second minima can be removed. But I think MRCI can give more physical data for this ground state.

Is there something wrong with my input file? How to remove it with MRCI approach?

Any comments and help are appreciated.

Thank you in advance,

 

Shilin Hou

 

Results(ACPF/cc-pcvqz):

      R     E1(HF)       DIP1        E2(CASSCF)       DIP2        E3(ACPF)          DIP3

    1.6   -776.2493090   0.17282959   -776.4200188   0.13818992   -776.5204776   0.23656468

    1.8   -776.3148194   0.65163519   -776.4839416   0.60620805   -776.5804423   0.68439505

    1.9   -776.3251340   0.88388333   -776.4937886   0.83099076   -776.5888267   0.90010015

    2.0   -776.3269510   1.11353675   -776.4954508   1.05297386   -776.5893276   1.11336495

    2.1   -776.3233233   1.34279372   -776.4920427   1.27395004   -776.5850192   1.32566006

    2.2   -776.3163261   1.57322444   -776.4858342   1.49535523   -776.5781622   1.53696369

    2.3   -776.3073476   1.80432337   -776.4788920   1.71816131   -776.5709855   1.74820085

    2.4   -776.2973052   2.03726534   -776.4746510   1.94288730   -776.5681313   1.95872143

    2.5   -776.2868008   2.27188611   -776.4804660   2.15765732   -776.5782443   2.16482483

    2.6   -776.2762266   2.50854076   -776.4823416   2.37699001   -776.5861416   2.37097908

    2.7   -776.2658324   2.74714894   -776.4760499   2.60049036   -776.5819935   2.58517957

    2.8   -776.2557688   2.98754186   -776.4673357   2.82661062   -776.5738194   2.80337286

 

 

***, CaF ground state

 r=[ 1.6 1.8 1.9  2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 ] ang

 do l=1,#r

 geometry={F;Ca,F,$r(l)}

 

  basis=cc-pcvqz

 !basis=cc-pcv5z

 

 { hf

     occ,9,3,3

      closed, 8,3,3

       wf,29,1,1 }

 

  e(1) = energy

  method(1) = program

  dip(1) = dmz

  bond(1) = $r(l)

  e1(l)= energy

  dip1(l)= dmz

 

      {casscf

     occ,14,5,5

      closed, 6,2,2

      frozen,6,2,2

      maxiter,40

       wf,29,1,1

      orbital,2140.2      }

 

e(2) = energy

  method(2) = program

  dip(2) = dmz

  bond(2) = $r(l)

  e2(l)= energy

  dip2(l)= dmz

 

  ! {MRCI

      {acpf

     occ,14,5,5

     closed, 6,2,2

     core,6,2,2

   maxiter,200,200

       wf,29,1,1

      orbital,2140.2   }

 

  e(3) = energy

  method(3) = program

  dip(3) = dmz

  bond(3) = $r(l)

  e3(l)= energy

  dip3(l)= dmz

 

 table,method,bond,e,dip

 enddo

 table, r,e1,dip1, e2,dip2,e3,dip3

---
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.molpro.net/pipermail/molpro-user/attachments/20170111/019e0be0/attachment-0001.html>