Molcas Forum

Bhumika

Member

Registered: 2024-02-06

Posts: 5

Dipole moment

I wonder if the origin of the dipole moment calculated by OpenMolcas is always the center of mass or cartesian origin ? For the neutral molecule it does not matter, but I am interested in the case when the molecule is not neutral.

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: Dipole moment

I think it's the center of mass. It should be printed in the output (for some print level, at least), and you can change it with the CENTER keyword.

Bhumika

Member

Registered: 2024-02-06

Posts: 5

Re: Dipole moment

Thank you for your response. Here is a screenshot of my example

 ++    Molecular properties:
      ---------------------

      Charge (e):
                      =   -2.0000
      Dipole Moment (Debye):
      Origin of the operator (Ang)=    0.0000    0.0000    0.0000
                   X= -6.9785E+01               Y= -2.4097E+01               Z=  4.3338E+00           Total=  7.3955E+01
      Center of Charge (Ang)
                     X=    7.26438507               Y=    2.50843868               Z=   -0.45113406
      Quadrupole Moment (Debye*Ang):
      Origin of the operator (Ang)=    4.9645    5.0961    3.3123
                  XX= -6.3083E+02              XY=  6.1114E+01              XZ=  2.2738E+02              YY= -3.4077E+02
                  YZ= -6.8369E+01              ZZ= -5.4282E+02
      In traceless form (Debye*Ang)
                  XX= -1.8903E+02              XY=  9.1671E+01              XZ=  3.4107E+02              YY=  2.4605E+02
                  YZ= -1.0255E+02              ZZ= -5.7024E+01

Also I have set of 2 molecules in my calculation and when I translate these the values change, so I don't think its center of mass actually.

Last edited by Bhumika (2024-09-19 16:25:46)

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: Dipole moment

It says "Origin of the operator (Ang)=    0.0000    0.0000    0.0000". For higher-order multipoles it seems it's the center of mass.