The talk was from Janos Pipek. I don't find a reference but I'll write a short story about it.
Every starting chemistry student is shocked after hearing that in spite of having this nice variational principle everything is only based on AOs and those AOs are all based on Gaussians. The way out is wavelet MRA, for example with a Daubechie function:
It has many nice properties:
That makes it a nice candidate for a basis function. They use it for jpeg compression and I am sure that they will soon use it in theoretical chemistry.