I need to utilize computational chemistry to study the catalytic process of para-orthohydrogen conversion involving catalysts. I have already found a relevant article (DOI: 10.1002/ntls.10002). However, since I personally have not used Molpro and am not specialized in computational chemistry, I would like to ask: Can Gaussian be used to simulate the para-orthohydrogen conversion process? If I aim to acquire the knowledge required to simulate such a process, what foundational materials or topics should I study to get started?