Nonlocal gradient-dependent correction

TDDFRT/TDHF mixture coefficients, as well as the composition of the approximate vxca, depend on the hybrid scheme used. Applications of the TDDFRT/TDHF approach with the hybrid functionals, such as the hybrid Becke s three-parameter functional [55] and the gradient correction of Perdew, along with his 1981 local correlation functional [45], B3P86, the Lee-Yang-Parr nonlocal correlation functional [56], B3LYP, or the Perdew-Burke-Erzenrhof (PBE) [57, 58] hybrid functional, PBEO [59], will be discussed below. 

Unfortunately, once we go to gradient-corrected functionals, the conceptual simplicity of the LSDA is lost and various models may be adopted. Consequently, many gradient-corrected XC energy functionals have been pro-posed.is-> 3o It is important to note that though these functionals have been referred to in the past as "nonlocal functionals, the gradient-corrected functionals are indeed mathematically local funaionals in that the values of e cfr), and ny point in space depend only the values and derivatives of... 

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