Chemical accuracy from small, system-adapted basis functions

Understand

We propose a general method for constructing system-dependent basis functions for correlated quantum chemical calculations.

• Our construction combines features from several traditional approaches: plane waves, localized basis functions, and wavelets.
• In a one-dimensional mimic of Coulomb systems, it requires only 2-3 basis functions per electron to achieve chemical accuracy, and reproduces the natural orbitals.
• We illustrate its effectiveness for molecular energy curves and chains of many atoms.