Command FLUX
The command FLUX requests the determination of the collision or photodissociation
flux as a function
of R using using data stored during a previous
calculation. For more details on the definition and determination of the flux
see:
M. H. Alexander, J. Chem. Phys. 95, 8931 (1991); 96, 6672 (1992).
D. E. Manolopoulos and M. H. Alexander, J. Chem. Phys. 97, 2527 (1992);
M. H. Alexander, C. Rist, and D. E. Manolopoulos, J. Chem. Phys. 97, 4836 (1992).
The command line syntax is
FLUX,{jobnam},IFLUX,{additional variables}
where
{jobname}: the jobname under which the wavefunction information
from the previous calculation is stored, as the file {jobname}.wfu
In order to create the {jobname}.wfu file, the
previous calculation must have
been carried out with the flags WAVEFL and AIRYFL
both set .TRUE.
IFLUX =
1: for a determination of the fluxes in the diabatic
(asymptotic) basis
−1: for a determination of the fluxes in the locally
adiabatic basis
2: for a determination of the adiabatic energies (see also the EADIAB command
−2: for fluxes summed over the sign of the additional
channel index
3: for fluxes in coordinate space
4: for determination of the transformation matrix C(R), defined in
Eq. (6) of the help file describing the close coupling method
If IFLUX = −1,1, or −2 then the {additional variables} are
THRESH, IPRINT, DAMP, INITIAL-J, INITIAL-L, and INITIAL-IND. These
are defined as follows:
THRESH: If the local wavevector in any channel is less than
THRESH, then the wavefunction component associated with
this channel is killed off. The default value of
THRESH is 0 for scattering calculations, and
-1.e+9 for photodissociation calculations
IPRINT: Normally, fluxes are not printed inside of any
energetically closed region. To print these out
set IPRINT not equal to zero. The default value of
IPRINT is 0 for scattering and 1 for photodissociation
DAMP: the damping factor for closed channel components (the
default value is one)
INITIAL-J: the rotational angular momentum of the initial channel
INITIAL-L: the orbital angular momentum of the initial channel
INITIAL-IND: the value of the additional index of the initial channel
In addition, channel fluxes are printed out ONLY for those channels which are specified in the
arrays JOUT and INDOUT.
For a photodissociation calculation it is not nessary
to specify THRESH, IPRINT, DAMP, INITIAL-J, INITIAL-L, or INITIAL-IND.
In this case the command line should be
If IFLUX = 3 then the {additional variables} are
NR, RMIN, DR, THRESH, IPRINT, and DAMP, where
NR: | NR | is the number of coordinate space
points at which the flux
is to be determined
if NR > 0, then the calculated flux is a sum over the flux
associated with all channels with positive values of the additional
index
if NR < 0, then the calculated flux is a sum over the flux
associated with all channels with negative values of the additional
index
RMIN: Minimum value of the internal coordinate r
DR: Step size in the internal coordinate r
THRESH: as defined above
IPRINT: as defined above
DAMP: as defined above
Coordinate state fluxes will be determined for all values
of the internal coordinate r ranging from RMIN to RMIN+(NR -1) DR
If IFLUX = 4 then {additional variables} designates
nstate: The number of states for which the asymptotic → locally
adiabatic transformation matrix is to be printed out
Rmin: The minimum value of R at which the asymptotic → locally
adiabatic transformation matrix is to be printed
δR: The step size
Rmax: The maximum value of R at which the asymptotic → locally
adiabatic transformation matrix is to be printed
If the variable δR is ≤ 0, then the transformation matrix is printed out just
for R=Rmin. Otherwise, the transformation matrix is printed out for
R=Rmin:δR:Rmax.
nstate cannot exceed 12, it will be truncated if the input value exceeds 12.
Fluxes are determined at all values of R lying
between RENDLD and RENDAI, with the
grid size and spacing controlled by the same parameters which govern the AIRY integration, namely
SPAC, FSTFAC, TOLAI, and RINCR.
The determination of collision and photodissociation fluxes
should be attempted only if you have a sophisticated understanding of the
time-independent quantum description of molecular collisions.
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