Program scatstab
This program performs the staticexchange scattering calculation with variational
correction using Pade approximants.
Input data records
iugeom, iuang, iugrd, iuanrd, iustpt, iupolt, iufege, iuxorb, iukmat
symtps
iGrnType
iUDipole
lna
itmax
cutkdf
excscl, lpotct
LMaxEx
iprnfg
NIntRegionR
PntFac
 If
iUDipole > 0
then read a data record in the format of the data record
DirProdOvlp.
 Data record in the format of the data record
OrbDegn.
 Data record in the format of the data record
EngForm.
 Data record in the format of the data record
ScatEng.
Data records from data file

EpsAsym,

optional data record that indicates where to truncate asymptotic integration. If this record is not present, then
take
iAsymCond = 1
and EpsAsym = cutkdf
.

TotalAsymp,

optional, form of the asymptotic potential.

Orthog,

optional, defines which orbitals the continuum wave function should be orthogonal to. This
overides the orthogonality constraints specified in the energy formulas (EngForm).
Definition of the input variables

iugeom
 input unit with geomertry.

iuang
 input unit with angular grid.

iugrd
 input unit with radial grid.

iuanrd
 input unit with angular cutoffs.

iustpt
 input unit sith static potential, if
iustpt < 0
then this
is positron scattering.

iupolt
 input unit with correlation/polarization potential. If this unit number is
≤ 0, then do not read in a polarization potential.

iufege
 input unit with local exchange potential. If this unit number is
equal to 0, then do not read in an exchange potential.
This would be the case in positron scattering. If this unit number is less
than zero then read from unit
abs(iufege)
an assume there is only
one exchange potential that does not depend on the scattering energy.

iuxorb
 input unit with single center expanded orbitals. If the unit number is less than or
equal to zero, then do not read in the orbitals.

iukmat
 output unit for the final variational matrix elements. If this is less than or equal to zero
then do not write the computed matrix elements to a file.

symtps
 character string
(LEN =7)
, the symmetry type of the continuum
orbital. If
the last two characters of this string are spaces, then this is assumed to
just the label of the IR and the last two characters are set to ' 1'
.

iGrnType
 integer, form of the Greens function to use.
iGrnType = 1
, then compute state with incoming spherical, and outgoing plane wave
boundary conditiosn. This is the form used in a photoionization calculation.
iGrnType = 0
, then compute state with standing wave
boundary conditions. This is the form used in a K matrix scattering calculation.
iGrnType = 1
, then compute state with outgoing spherical, and incoming plane wave
boundary conditions. This is the form used in a T matrix scattering calculation.

iUDipole
 integer flag that controls the type of calculation.
 If
iUDipole <= 0
then do normal K matrix calculation.
 If
iUDipole > 0
then read functions <f
from this unit
then compute <fpsi>
using the variational method.

lna
 integer, maximum l used in the homogeneous solutions. This thus controls
the dimension of the computed variational matrix.

itmax
 integer, maximum number of interations allowed in the Pade approximant sequence.

cutkdf
 real number, parameter that controls the convergence of the matrix elements in the Pade sequence.
See the description of the data record
CnvgKMat.

excscl
 real number, exchange scale factor. The exchange potential is multiplied by this
number.

lpotct
 integer, maximum l included in the partial wave expansion of the
potential. If
lpotct < 0
then include all possible terms in the expansion.

LMaxEx
 integer, maximum l included in the
1/r_12
expansion of theexchange
potential. If LMaxEx < 0
then include all possible terms in the expansion.

iprnfg
 integer, print flag.
 If
iprnfg = 0
then just print the iterative cross section.
 If
iprnfg = 1
then print the variational matrix elements on each iteration.
 If
iprnfg = 2
then print the variational correction on each iteration.
 If
iprnfg = 3
then print the other matrices.
 If
iprnfg = 4
then print the selected wave functions.

NIntRegionR
 integer, number of stabilization regions.

PntFac
 real, factor for number of points in asymptotic region. The higher the number the smaller the
integrations steps. A reasonable value is 30.0.