Electrocaloric response of KNbO3 from a first-principles effective Hamiltonian

•It is the first time that the electrocaloric response of KNbO3 is reported.•The results are explained in terms of the bonding by comparing KNbO3 to BaTiO3, which is a well-studied compound.•The results are well represented by a regression that allows for their application to engineering projects.

The electrocaloric response of KNbO3 is calculated using a first-principles based effective-Hamiltonian. Both indirect and direct molecular dynamics simulations are used to determine the adiabatic temperature change as a function of temperature and applied electric field. Both the magnitude of the electrocaloric response, ΔTmax, and the temperature where the maximum is observed, T*, are comparable for both molecular dynamics approaches. The results are well represented by a simple second-order regression.