2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36681We discuss new Majumdar-Papapetrou solutions for the 3+1 Einstein-Maxwell equations, with charged dust acting as the external source of the fields. The solutions satisfy non-linear potential equations which are related to well-known wave equations of 1+1 soliton physics. Although the matter distributions are not localised, they present central structures which may be identified with voids.6 pages, LaTeX. Talk delivered at the Spanish Relativity Meeting. Bilbao, Spain, September 7-10, 1999General Relativity and Quantum Cosmologytext