Charge-transfer-like π→π* excitations in time-dependent density functional theory: A conundrum and its solution

نتاج البحث: نشر في مجلةمقالةمراجعة النظراء

ملخص

We address the conundrum posed by the well-known failure of time-dependent DFT (TDDFT) with conventional functionals for "charge-transfer-like" excitations in oligoacenes. We show that this failure is due to a small spatial overlap in orbitals obtained from the underlying single-electron orbitals by means of a unitary transformation. We further show that, as in true charge-transfer excitations, this necessarily results in failure of linear-response TDDFT with standard functionals. Range-separated hybrid functionals have been previously shown to mitigate such errors but at the cost of an empirically adjusted range-separation parameter. Here, we explain why this approach should succeed where conventional functionals fail. Furthermore, we show that optimal tuning of a range-separated hybrid functional, so as to enforce the DFT version of Koopmans' theorem, restores the predictive power of TDDFT even for such difficult cases, without any external reference data and without any adjustable parameters. We demonstrate the success of this approach on the oligoacene series and on related hydrocarbons. This resolves a long-standing question in TDDFT and extends the scope of molecules and systems to which TDDFT can be applied in a predictive manner.

اللغة الأصليةالإنجليزيّة
الصفحات (من إلى)2408-2415
عدد الصفحات8
دوريةJournal of Chemical Theory and Computation
مستوى الصوت7
رقم الإصدار8
المعرِّفات الرقمية للأشياء
حالة النشرنُشِر - 9 أغسطس 2011

All Science Journal Classification (ASJC) codes

  • !!Computer Science Applications
  • !!Physical and Theoretical Chemistry

بصمة

أدرس بدقة موضوعات البحث “Charge-transfer-like π→π* excitations in time-dependent density functional theory: A conundrum and its solution'. فهما يشكلان معًا بصمة فريدة.

قم بذكر هذا