Softwares

To tackle various issues of structural isomerism, we have built a python code and a bash shell script that would help to get the various permutations and combinations for a given structure:

For example, let's take one of the isomers of Si6C15

   21

scf done: -2307.069785

 C     3.450463    -0.000000     1.000000

 C    -1.725231     2.988188     1.000000

 C    -1.725232    -2.988188     1.000000

Si     4.207633     1.764259     1.000000

Si     4.207633    -1.764260     1.000000

 C     2.573322     1.162444     1.000000

 C     2.573321    -1.162444     1.000000

 C     1.225426     0.707892     1.000000

 C     1.225426    -0.707892     1.000000

Si    -0.575923     4.526047     1.000000

Si    -3.631709     2.761788     1.000000

 C    -0.279954     2.809784     1.000000

 C    -2.293366     1.647340     1.000000

 C     0.000340     1.415196     1.000000

 C    -1.225766     0.707304     1.000000

Si    -3.631710    -2.761787     1.000000

Si    -0.575924    -4.526047     1.000000

 C    -2.293367    -1.647340     1.000000

 C    -0.279955    -2.809784     1.000000

 C    -1.225766    -0.707304     1.000000

 C     0.000339    -1.415196     1.000000

If we need to think about various permutations and combinations of this one structure (putting Si atoms at different positions) manually then it will come a laborious task. On the contrary, the following python script written by us would give various possibilities. Let's save the optimized Cartesian coordinates of this structure as freq-c1.xyz. Then execute the code:

python3 coord.py freq-c1.xyz