Editorial

This issue of Molecular Physics features the next in a new series of invited review articles, ‘Ideas of relativistic quantum chemistry’ by Prof. Wenjian Liu of Peking University 1. This article follows the previous review in the series, 'Good Vibrations: Probing Biomolecular Structure and Interactions through Spectroscopy in the Gas Phase', by Prof. John Simons 2, and the publication in 2008 of a collection of reviews 3 covering some of the most important areas of interest to the journal's readership to celebrate the 50th anniversary of Molecular Physics.

Wenjian Liu's topical review focuses on relativistic quantum chemistry, a topic that is absolutely fundamental to all of quantum chemistry. His review gives a comprehensive survey of recent developments in the fundamental theory, which are expected to have increasing significance for practical electronic structure calculations in the future. At the level of molecular properties, the important role of relativistic effects is apparent in many papers recently published in Molecular Physics. For instance studies of Tc₂ and Re₂ 4, the CUO trimer 5, and the UX₄ tetrahalides 6 exemplify the need for adequate treatment of relativistic effects in predicting structure and potential surfaces of molecules containing heavy elements. Hyperfine structure in spectroscopy is a related area that is well-illustrated by a joint theory-experimental study of bromofluoromethane 7, as well as a comprehensive review on quadrupole moments 8. Group theoretical considerations are foremost in another recent article on bismuth and antimony clusters 9.

Molecular Physics has a long-standing tradition of excellence in quantum chemistry, and continues to welcome new research article submissions in this broad area, as well as within the subfield of relativistic quantum chemistry that is highlighted by Wenjian Liu's article. We draw the reader's attention to the recent Special Issues in honor of former Molecular Physics Editor Henry F. Schaefer 10, and current Molecular Physics Editor Hans-Joachim Werner 11. We intend to publish further topical reviews on other aspects of quantum chemistry in the future, as a complement to the present article, and the earlier 50th anniversary review on ‘Quantitative quantum chemistry’ 12.