Born in 1963 in Ahaus (Westphalia, Germany), Prof. van Wüllen studied chemistry from 1983 to 1988 at the University of Münster and graduated there with Prof. Martin Klessinger, working on the semiempirical calculation (geometry optimization and vibrational analysis) of excited states of small organic molecules.He then moved to the university of Bochum, where he did his Ph.D. work together with Prof. Werner Kutzelnigg (from 1988 to 1992). In the course of this work, Prof. van Wüllen developed the MC-IGLO program which calculates magnetic susceptibilities and n.m.r. chemical shifts using multiconfiguration-Hartree-Fock wave functions.

His research interest then (1993) switched to density functional theory (DFT), especially the calculation of relativistic effets within the DFT framework. He developed new computational approaches based either on "direct perturbation theory" or the so-called "regular approximation" (ZORA). He got his habilitation in 1997 at the University of Bochum.

From 2000 to 2007, he held a position as a university professor (C3) at the TU Berlin. Since 2007, he holds the chair (W3) of Theoretical Chemistry at the TU Kaiserslautern.