AI model for computational chemistry and scientific computing

As a researcher involved in quantum chemistry, I'm currently engaged in studying and modifying the source codes of some computational chemistry software like openmolcas, gromacs and gamess to fix some bug and add some customized features, largely implementing GPU parallelization for a certain modules like electron repulsion integrals. I need an ai code assistant like cody or copilot that is more knowledgeable with computational chemistry and scientific computing to assist me with the process. I need some advice on choosing an llm and fine tune it if necessary.

Required Expertise:
- AI code assistant, large language models
- Knowledge in scientific computing and computational chemistry, fortran
- Capability to communicate complex concepts in a simplified manner.