This is off to me. I have not worked in that language in years but it was adopting c-like features decades ago. In our computational code, we replaced all mem

This is off to me. I have not worked in that language in years but it was adopting c-like features decades ago. In our computational code, we replaced all memory allocation, system interface and I/o code with c, leaving the fortran code as basically algebra. That was far easier for the vector computer compilers to optimize due to well defined memory usage and layout. There was a tremendous amount of work in compilers for this stuff which can’t have gone away. I would think that algebra and matrix math should be effective in any language that can be properly compiled for the architecture. Assuming an intermediate language or layer in the compiler, c and fortran (and other languages) share the working bits of the compiler. Well designed codes should be fine. And I assume lanl has good math. Good libraries also. Some tuning might be required as architectures change but math code looks the same. Given a consistent api, the cs intensive stuff stuff can be in a different language calling libraries. Psi4 implements qm calculations in a python top level package.