Antiparticles—subatomic particles that have exactly opposite properties to those that make up everyday matter—may seem like a concept out of science fiction, but they are real, and the study of matter-antimatter interactions has important medical and technological applications. Marcos Barp and Felipe Arretche from the Universidade Federal de Santa Catarina, Brazil have modelled the interaction between simple molecules and antiparticles known as positrons and found that this model agreed well with experimental observations. This study has been published in The European Physical Journal D.