* use pure openbabel class without conversion ([454](https://github.com/njzjz/reacnetgenerator/issues/454)) ([ae80192](https://github.com/njzjz/reacnetgenerator/commit/ae80192))
* use cython to accelarate numpy process ([452](https://github.com/njzjz/reacnetgenerator/issues/452)) ([5a19b1c](https://github.com/njzjz/reacnetgenerator/commit/5a19b1c))