Rights:
© 1993 American Physical Society (APS). This is the accepted version of the following article: Alatalo, M. & Nieminen, Risto M. & Puska, M. J. & Seitsonen, A. P. & Virkkunen, R. 1993. Phosphorus vacancy in InP: A negative- U center. Physical Review B. Volume 47, Issue 11. 6381-6384. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.47.6381, which has been published in final form at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.47.6381.