Explicitly correlated Gaussians with tensor pre-factors: analytic matrix elements

We consider a specific form of explicitly correlated Gaussians – with tensor pre-factors – which appear naturally when dealing with certain few-body systems in nuclear and particle physics. We derive analytic matrix elements with these Gaussians – overlap, kinetic energy, and Coulomb potential – to be used in variational calculations of those systems. We also perform a quick test of the derived formulae by applying them to p- and d-waves of the hydrogen atom.