APG

[lelemmen]

Describe the feature you'd like
Conceptually, APG is the most flexible geminal inside a given spinor/bispinor space. I would like to implement

• spinor APG
• bispinor APG

Describe what the current code offers in relation to what it lacks

• It offers no possibilities for 4C bases yet
• There is no support yet for APG 'variables'
• We need different solvers for when the number of equations is equal/larger than/smaller than the number of parameters

[lelemmen]

Before implementing APG in the relativistic case, we'd have to first determine all the correct building blocks for relativistic calculations: the one- and two-electron integrals, transformation matrices, bispinor bases and density matrices.