[CPMD-list] second order chemical reaction

[Dah-Yen Yang]

Dear Prof. Hutter:
    We are currently testing chemical reaction by CPMD.  I have some
puzzles with the following questions:

1. How to construct pseudopotentials and pseudowavefunction for cation
and anion?
    We have tested to use neutral atomic pseudopotential, for example
Cl, and use the "ATOMIC CHARGE" with value -1.0 to run Cl- anion.
However we always get the same neutral result.  Should we use anion Cl-
pseudopotentials?

2. In your paper, Chem Phys. Lett., 321(2000)225, about proton transfer
how to generate H+ cation pseudopotential?
According to Fig. 2 in that paper, it seems to me all of the atoms of
(H2O)3H+ move.  Does H+ transfer to water 3??

3. If the answer for question 1 is that we have to use negative charged
pseudopotentials, then this question is puzzle to us.
We want to study Cl- anion(incoming) + ClCCH2CN, S_N2 reaction, the
incoming Cl- has to  use negative charged pseudopotentials and the
outgoing Cl at beginning has to use neutral pseudopotentials.  After the
reaction the incoming particle has to use neutral pseudopotential and
the outgoing Cl has to use negative charged pseudopotentials.  This
question is similar to question 2.

If the answer for the anion and cation pseudopotentials should all use
neutral pseudopotentials, then how to make "ATOMIC CHARGE" works?

4. We want to study another S_N2 reaction of O(1D) +CH4, where 1D is the
term symbol.  The oxygen is in its excited state.  Can we use tddft to
excite oxygen atom to its excited state and then write out its
wavefunction with fixed term symbol.  How and which files story this
information?
Then the next question is to read in the restart file for oxygen only
and put CH4 as initial run.  Can this work? and how?

Best regards.

Dah-Yen Yang