Quantum chemistryâ€”more specifically, electronic structure theoryâ€”is the branch of molecular simulation which models the distribution of electrons about nuclei.

To run a quantum chemical calculation, one must specify a number of parameters:

- The identity and position of all atoms in one's molecule/molecules.
- The level of theory which the calculation will employ, which typically consists of a "method" and the basis set used to describe the electron distribution.
- The task you wish to perform (e.g. "energy," "forces," "dipole").
- (Optional) The specific settings to employ for the calculation, which in Rowan are grouped together into "modes."

To read more about how Rowan handles each of these parameters, check out the subsections to the left!

Rowan supports quantum chemistry calculations through a number of underlying engines: PySCF for Hartreeâ€“Fock and density-functional theory, xTB for semiempirical calculations, and AIMNet2 for machine-learned interatomic potential calculations. Support for additional engines is planned for the future!