Command ScatPos
Command format
ScatPos
Energy1 Energy2 ...
or
ScatPosN
EnergyStart EnergyStep NumberofEnergies
This command computes the K or T scattering matrix
for positronmolecule scattering.
The ScatPos
form does the calculation at
a list of scattering energies (in eV). If no energies are present then the energies are
taken from the
ScatEng,
or
ScatEngN,
data records.
The ScatPosN
form does the calculation at
a sequence of scattering energies with fixed spacing (in eV).
If the command
FileName
has been used to define the MatrixElements
file,
then the final K or T matrix elements
are written to the that file. Otherwise, the matrix elements
are written to a scratch file.
Data records used

ScatEng,
scattering energy, in eV. This data record is not used if
Energy is defined in the command.

ScatEngN,
scattering energy, in eV. This data record is not used if
Energy is defined in the command.

ScatContSym,
the IR of the continuum orbital.

EngForm,
potential energy formula.
This data record can be created using the
GenFormPhIon
or
GenFormScat
commands.
Optional data records used

FegeScale,
Optional value used to scale the local exchange potential. This can be used
to curcumvent singularities in the interative procedure.
Default value is 1.0.

GrnType,
Optional, the type of the scattering matrix (1, 0, or 1).
Default value is 0 for a T matrix calculation.

NIntReg,
number of regions used in stabilization.
Default value is 40.

EpsAsym,
this data record controls where the asymptotic integration is truncated.
The default is to stop the integration when the asymptotic potential is less than
CnvgKMat/10 times the asymptotic electron kinetic energy.

TotalAsymp,
controls the form of the asymptotic potential.

RungeKuttaFac
this integer controls the step size used in the differential equation integrator.
Higher values yields smaller step sizes.
Default value is 4.

HFacWaveAsym,
a real number that is used to generate the asymptotic radial grid. The higher the value the
more dense the grid will be between for r greater than RMax.
Default value is the value of HFacWave used to generate the grid, the default value
for that parameter is 10.

LMaxK,
the maximum l used in the expansion of the
homogeneous scattering solution. This is thus the dimension of the scattering matrix.
Note that this should be greater than or equal to
LMaxA. Default value is LMaxA2.

NAsymLRange,
the range of the functions on the left of the variational expression that should be
computed. The default value is to use the full range up to NAsymL.
Examples of use

test27
positron scattering from CH_{4}.