Foreword to the special issue on the “Electronic structure: principles and applications (ESPA 2022)” conference

The ESPA (Electronic Structure, Principles and Applications) conference is organized every two years in Spain. It brings together international specialists in theoretical and computational chemistry to present and discuss the latest advances in this field. The first edition was held in Madrid in 1998, and then, subsequently, in San Sebastián, Sevilla, Valladolid, Santiago de Compostela, Palma de Mallorca, Oviedo, Barcelona, Badajoz, Castellón, and Toledo. The 12th edition of the conference could not be held in 2020 due to the covid epidemic, and it was held in Vigo from June 21 to 24, 2022. This special issue assembles a collection of articles from presentations given at the conference.