Molcas Forum

zorkov

Member

Registered: 2016-06-04

Posts: 4

Bug report : DENSITY in RASPT2 leads to wrong results

The following input performs a RASSCF/RASPT2 calculation and uses PROPERTIES + DENSITY to calculate properties at the RASPT2 level.

&GATEWAY
  Symmetry = X Y
  RX2C
  Basis set
    H.ano-r...3s2p1d.
    H      0.000000    0.000000    1.000000    Angstrom
  End of basis
  Basis set
    F.ano-r...4s4p2d1f.
    F      0.000000    0.000000    0.000000    Angstrom
  End of basis

&SEWARD

&SCF

&RASSCF
Symmetry  = 1
Spin      = 1
CIROOT    =  1  1  1
Frozen    =  0  0  0  0
Inactive  =  2  0  0  0
Ras2      =  1  1  1  0
Ras3      =  2  0  0  0
NActEl    =  6  0  2
Lumorb

 &CASPT2 &END
Frozen     = 1  0  0  0
DENSity
PROPerties

This calculation results in an error where the net charge is not zero.

      Total electronic charge=   10.000035

      Total            charge=   -0.000035

However, if the keyword DENSITY is removed, or the calculation method is changed to CASSCF/CASPT2, then the above error does not occur. For complex systems (such as those containing transition metals), this bug can lead to incorrect population results and MS-CASPT2 energies. For example:

      Total electronic charge=-9245.834505

      Total            charge= 9323.834505

       Total RMS-CASPT2 energies:
::    RMS-CASPT2 Root  1     Total energy:****************
::    RMS-CASPT2 Root  2     Total energy:****************
::    RMS-CASPT2 Root  3     Total energy:****************

I have tested several versions from 2023 to the latest, and this issue exists in all of them.

Last edited by zorkov (2026-04-04 18:29:53)

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,204

Re: Bug report : DENSITY in RASPT2 leads to wrong results

As far as I know, there are reasons to believe the DENSITY keyword is broken. This may be just one of them.

PS. Bugs are better reported in the GitLab page: https://gitlab.com/Molcas/OpenMolcas/-/work_items