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Next: Parallel atsp2K Up: Computing Atomic Transitions Previous: Computing Allowed Transitions   Contents

Computing Forbidden Transition

Both biotr and trans are used to compute forbidden transitions. biotr computes the angular data storing it in the memory and it executes faster. When orbitals in the initial and final state are orthogonal, the program trans may be used. This happens often to be the case for forbidden transitions between levels of a Breit-Pauli calculation. For example, the example below demonstrate the interactive use of trans. To determine the E2 transitions between the E1 and O1 states discussed in the previous section, the interactive session is shown below:
#  ........An E2 transition between two odd parity states........
  Name of Initial State
I
  Name of Final State
F
  intermediate printing (y or n) ?
n
  transitions only for E(initial) < E(final) (y or n) ?
y
 Default Rydberg constant (y/n)
y
  Relativistic calculation ? (y/n)
y
  Type of transition ? (E1, E2, M1, M2, .. or *)
E2
  Use existing file for Angles ? (y/n)
n
------------------------------------------------------------------------

The above calculation produces two files: I.F.lsj which contains the data about each transition and it has the same format as the file from the former section, and the angular information is stored in I.F.E2. The latter is binary and in the case of an iso-electronic sequence, the angular data can be

A script below is shown which uses biotr for computing the forbidden transitions. Note that the script is very general, it computes for each combination of output and input state, and additionally for each of the the forbidden E2, M1, M2.

set -x
# compute forbidden transitions, in general biotr and trans can be 
# used for this purpose, here the use of biotr is shown. trans use
# similar set of input parameters. 

echo "computing *.j files"
# in this case we use n=4 calculation.
n=4

# copy configuration lists
cp E4.c E1.c
cp O4.c O1.c

I=E1
F=O1

# start a loop over forbidden transitions E2, M1, M2
for T in E2 M1 M2
do
   (for I in E1 O1
   do
      (for F in E1 O1
      do
         (for Z in 8 9 
         do
            (echo
         
# remove files that may stay from previous calculation
            rm I.F.???

# copy initial files into I.c I.w I.j 
            cp ${I}.c I.c
            cp ../${I}/${I}.${Z}_${n}.w I.w
            cp ${I}.${Z}.j I.j
# copy final into F.c, F.w, F.j 
            cp ${F}.c F.c
            cp ../${F}/${F}.${Z}_${n}.w F.w
            cp ${F}.${Z}.j F.j
#run biotr         
${ATSP}/bin/biotr<<EOF
I
F
n
y
${T}
EOF

# save the computed transitions under unique name incorporating
# Initial state, Finals state, type of transitions, and Z. 
            mv I.F.lsj F_${T}_${I}.${F}.${Z}.lsj 
      
            echo)
         done)
      done)
   done)
done


# remove not needed files.
rm ?.?  fort*

Finally sh_tables tabulates the computed data in several files: Energy data and lifetimes *-lev.dat and the transition data stored in *-lin.dat. Both are tabulated from data found in *.j and *.lsj.


next up previous contents
Next: Parallel atsp2K Up: Computing Atomic Transitions Previous: Computing Allowed Transitions   Contents
2001-10-11