In density functional theory (DFT) the exchange-correlation energy has to be approximated. One of the most widely used approximations to the correlation component, the Lee-Yang-Parr (LYP) functional does not obey nonuniform scaling requirements. We propose a modifying function that makes this functional satisfy nonuniform scaling constraints. As a result, two modified LYP functionals are suggested. One of them, optimized in a preliminary way, exhibits some properties better than the original LYP functional. This implies that nonuniform scaling requirements convey very important information and all approximate functionals in DFT should be made to satisfy these requirements. Our modifying factor could be used to improve the nonuniform scaling properties not only of E,LY'[ n] but also of most functionals which do not obey these conditions. 0 1996 John Wiley & Sons, Inc. is attractive for large systems because the density depends only upon three spacial coordinates, regardless of the size of the system [l-41. For computational purposes the exact exchangecorrelation (xc) functional, Ex,[ n], must be approximated, and conveniently Ex,[nl is separated in the following way, Ex,[ n] = Ex[ n] + E,[ n] (Ref.