**(Medium)** A complete overhaul of the Qiskit Chemistry module, plus the new Qiskit Gradients framework, meant both for quantum application developers as well as domain experts with basic knowledge of quantum computing has been announced. These enhancements represent an important step toward frictionless quantum computing, where developers can write applications reaping the benefits of quantum computers without concerning themselves with the intricacies of the hardware.

The easiest way to explore the tools introduced is to install the latest Qiskit version and start playing around with the newly released tutorial notebooks for chemistry and gradients. In addition, you can check out the Qiskit slack workspace to connect with other Qiskit users and contributors.

The team designed the new Qiskit Chemistry module to be both modular and extensible, while providing high-level applications that make programming more intuitive for anyone interested in quantum computing. The module includes algorithms for calculating molecules’ electronic and vibronic structure, plus algorithmic primitives to serve as the building blocks for higher level applications. Recently, the Qiskit group teamed with ExxonMobil scientists to compute thermodynamic observables for the hydrogen molecule on the ibmq_valencia quantum processor using Qiskit.

the new Qiskit Gradients framework provides an automated way to compute analytic gradients — basically, how the circuit is changing as the variational algorithm runs — as well as functions of the gradients for a variety of problem classes.

Simulating quantum systems on classical computers has been one of the greatest challenges for the quantum physics and quantum chemistry communities for the past few decades.

A fundamental algorithmic building block of the Chemistry module is the Ground State Solver, i.e., the ability to approximate the ground state for a given problem.

In addition to approximating ground states, it is also important to be able to compute excited states and their corresponding energies. To this extent, Qiskit Chemistry offers Excited States Solvers such as a generic Eigensolver-based calculation that can be used with generic eigensolvers as well as the Quantum Equation of Motion (QEOM) algorithm.

The Ground State and Excited States Solvers allow end users to evaluate properties of a given molecule. However, for many applications it is also important to see how properties change e.g. with changing molecular geometry or by varying other input parameters. With this release, Qiskit Chemistry supports a generic Molecule object that allows perturbation of different degrees of freedom (e.g. interatomic distance, molecule bending etc.).