ɪn nˈaɪntiːnhˈʌndɹɪd sˈɪksti sˈɪks hiː stˈɑːɹɾᵻd hɪz wˈɜːk æz lˈɛktʃɚɹɚ ænd ðˈɛn fˈʊl pɹəfˈɛsɚ fɹʌm nˈaɪntiːnhˈʌndɹɪd sˈɪksti nˈaɪn æt ðə jˌuːnɪvˈɜːsᵻɾi ʌv ˈæntwɜːp, wˌɛɹ hiː fˈaʊndᵻd ðə ɹᵻsˈɜːtʃ ɡɹˈuːp tˌiːˌɛfvˌiːˈɛs θˈiəɹɪtˌɪʃ fˈaɪsɪkə vˈæn də vˈæst stəfˈɛn.
In 1966 he started his work as lecturer and then full professor (from 1969) at the University of Antwerp, where he founded the research group TFVS (Theoretische Fysica van de Vaste Stoffen).