Our in-house program QUEST provides a wide range of electronic structure theories for calculating the ground state energies and properties of molecular systems. All of the methods implemented can be applied with either standard Gaussian basis sets or using London atomic orbitals to allow for studies in the presence of strong external electromagnetic fields. Density-fitting techniques may be used throughout to accelerate calculations.

#### Density Functional Approaches

- (Current)-Density-Functional Theory at LDA / GGA / mGGA / hybrid /range-separated hybrid / double-hybrid levels
- Orbital-Free Density-Functional Theory
- Optimized Effective Potential based Density-Functional Theory

#### Correlated Wavefunction Theories

- Møller-Plesset Theory: MP2, MP3
- Random Phase Approximation Techniques: dRPA, RPA, SOSEX
- Coupled Cluster Theory: drCCD, rCDD, CCD, CCSD, CCSD(T)