[CPMD-list] tddft properties BIS

[Eneritz Muguruza]

Dear CPMD users,

    I sent an email in January (I copy it below) asking about the 
DIPOLE MOMENT calculation in a TDDFT calculation. I got a different 
result for the ground state dipole moment when performing a dipole 
moment calculation of the ground state after a wavefunction 
optimization and doing a property calculation within TDDFT. I was told 
that new code did not have this problem, however I have repeated the 
calculations with the latest release CPMD.3.11.1 and I get the same 
results as I did with the old one. Any clue what is going on?
I did check that the results from the ground state differ by a shift of 
32.61 Debye on the z component of the dipole moment, and the values of 
the z component of the dipole moment of the excited states are around 
this number, is it possible that the values of the z component of the 
dipole moment on the excited state are shifted by the same value?

      Thank you,

                   Eneritz


Dear CPMD users,

       I am trying to calculate properties (charge distribution and dipole
moment) of excited states of an isolated molecule obtained with TDDFT. I have
tried this by writingthe PROPERTY keyword in the TDDFT section. In this way I
obtained the forces, partial charges of atoms and dipole moment in the ground
state and excited states. However the Z component of the dipole
moment of the ground state obtained with this procedure
DIPOLE MOMENT
           X           Y           Z         TOTAL
     1.32608    -0.00130    13.02980       13.09711  atomic units
     3.37059    -0.00331    33.11869       33.28976  Debye

differs very much respect to an independent ground state Dipole moment
calculation:
DIPOLE MOMENT
           X           Y           Z       TOTAL
     1.32558    -0.00140     0.20019     1.34062   atomic units
     3.36932    -0.00355     0.50883     3.40753   Debye

The value of the ESP charges in the ground state come into accord.

As I said this is an isolated molecule and I am doing the calculations in an
orthorombic box.

         Is there any problem with the implementation of the dipole 
moment calculation for isolated system with orthorombic box for the 
TDDFT
calculations? If the ground state dipole moment of the ground state is wrong
the values for the excited state might be wrong as well. What about the charge
distribution?

      Thank you very much,


                    Eneritz
-- 
Eneritz Muguruza
eneritz.muguruza at kcl.ac.uk