To get a deeper understanding of electronic structure methods, like Hartree-Fock, MP2, and Coupled Cluster method, there are many small programs (codes) available in Python, C++ or Fortran, for example, Daniel Crawford's website, Joshua website
Does any one know any implementation of a simple Antisymmetrized Product of Strongly-orthogonal Geminals (APSG) method (Geminal Model Chemistry) for, say, two geminals (LiH, or H4, etc.) in Python or another programing language?
I will be grateful if someone can share this type of code (implementation) to get a better understanding of geminal based methods.