This topic was first broached about four years ago and I wanted to know if anyone has tried using c++ programs as executables/scripts instead of python?
Is there a way to either call headers (.h) or program files (.cpp) for functions and data structures within a new standalone executable file (e.g. 'hello-world-psi4.cpp) and from that executable run a geometry optimization and recover the geometry and charge of the optimized molecule?
Accessing Psi4 structures from a C++ program sounds like a job for our plugin system. I don’t use plugins, so I’m afraid I can’t be of any further help than that.
I assume it is possible to some extend, but certainly not ready-to-use. There is no explicit C++ API with documentation in the sense Boost or Eigen etc do offer.
Avoiding python completely is difficult as most logic and input handling is done at the python level. Some features won’t work without python at all.
It is somewhat easier for post-scf methods as they are usually self-contained modules.
Running a geometry optimization from a C+±only program will require a lot of work to get the very basics running I assume.
Plugins are the way to go to get C++/python programs relying on the PSI4 eco system.