# Qiskit tutorials: Chemistry¶

Click any link to open the tutorial directly in Quantum Lab.

Electronic structure - This tutorial describes how to use a quantum computer to solve the electronic problem.

Vibronic structure - The nuclear Schroedinger equation is usually solved in two steps, in analogy with its electronic counterpart. A single-particle basis is obtained either by the harmonic approximation applied to the Potential Energy Surface (PES), or from a vibrational self-consistent field (VSCF) calculation. Vibrational anharmonic correlations are added

*a posteriori*with perturbative or variational approaches. The latter include Vibrational Configuration Interaction (VCI) and Vibrational Coupled Cluster (VCC) for highly-accurate anharmonic energies. However, their applicability is limited to small molecules with up to about 10 atoms due to their unfavorable scaling with system size. This tutorial tackles the scaling problem by using quantum algorithms.Ground state solvers - This tutorial discusses the ground state calculation interface of Qiskit Chemistry. The goal is to compute the ground state of a molecular Hamiltonian. This Hamiltonian can be electronic or vibronic. To learn more about the preparation of the Hamiltonian, check out the electronic structure and vibronic structure tutorials (described above).

Excited states solvers - This tutorial discusses the excited states calculation interface of Qiskit Chemistry. The goal is to compute the excited states of a molecular Hamiltonian. This Hamiltonian can be electronic or vibronic. For information about the preparation of the Hamiltonian, check out the electronic structure and vibronic structure tutorials (described above).

Sampling the potential energy surface - This interactive notebook demonstrates how to utilize the Potential Energy Surface (PES) samplers algorithm of Qiskit Chemistry to generate the dissociation profile of a molecule. It uses the Born-Oppenhemier Potential Energy Surface (BOPES) and demonstrates how to exploit bootstrapping and extrapolation to reduce the total number of function evaluations in computing the PES using the Variational Quantum Eigensolver (VQE).

Calculating thermodynamics observables with a quantum computer See this paper for more information on this tutorial.