Fractional paradigms in quantum chemistry

Abstract The realization of fractional quantum chemistry is presented. Adopting the integro‐differential operators calculus arbitrary‐order, we develop a general framework for description nonlocal effects in complex electronic environments. After brief overview historical and fundamental aspects various classes Schrödinger equations are discussed pertinent controversies open problems around their applications to model systems detailed. We provide unified approach toward generalization chemical models such as Hartree–Fock Kohn–Sham density functional theory variants molecular integrals correlation energy. Furthermore, offer strategies modeling static‐ dynamic‐order through constant‐ variable‐order operators, respectively. Possible directions future developments also outlined.