Assessment of density functional methods for exciton binding energies and related optoelectronic properties
نویسندگان
چکیده
منابع مشابه
Time-dependent density-functional approach for exciton binding energies
Optical processes in insulators and semiconductors, including excitonic effects, can be described in principle exactly using time-dependent density-functional theory TDDFT . Starting from a linearization of the TDDFT semiconductor Bloch equations in a two-band model, we derive a simple formalism for calculating exciton binding energies. This formalism leads to a generalization of the standard W...
متن کاملdiagnostic and developmental potentials of dynamic assessment for writing skill
این پایان نامه بدنبال بررسی کاربرد ارزیابی مستمر در یک محیط یادگیری زبان دوم از طریق طرح چهار سوال تحقیق زیر بود: (1) درک توانایی های فراگیران زمانیکه که از طریق برآورد عملکرد مستقل آنها امکان پذیر نباشد اما در طول جلسات ارزیابی مستمر مشخص شوند; (2) امکان تقویت توانایی های فراگیران از طریق ارزیابی مستمر; (3) سودمندی ارزیابی مستمر در هدایت آموزش فردی به سمتی که به منطقه ی تقریبی رشد افراد حساس ا...
15 صفحه اولValidation of Koopmans' theorem for density functional theory binding energies.
Both initial state effects, to a good approximation the electrostatic potential at the nucleus, and final state effects, due to the response of the electrons to the presence of the core-hole, contribute to core-level binding energies, BE's. For Hartree-Fock, HF, wavefunctions, Koopmans' theorem, KT, which states that the initial state BE = -ε ιs rigorous. However, the KT relationship is commonl...
متن کاملEffect of Curvature on the Mechanical Properties of Graphene: A Density Functional Tight-binding Approach
Due to the high cost of experimental analyses, researchers used atomistic modeling methods for predicting the mechanical behavior of the materials in the fields of nanotechnology. In the pre-sent study the Self-Consistent Charge Density Functional Tight-Binding (SCC-DFTB) was used to calculate Young's moduli and average potential energy of the straight and curved graphenes with different curvat...
متن کاملBenchmark ab Initio Conformational Energies for the Proteinogenic Amino Acids through Explicitly Correlated Methods. Assessment of Density Functional Methods.
The relative energies of the YMPJ conformer database of the 20 proteinogenic amino acids, with N- and C-termination, have been re-evaluated using explicitly correlated coupled cluster methods. Lower-cost ab initio methods such as MP2-F12 and CCSD-F12b actually are outperformed by double-hybrid DFT functionals; in particular, the DSD-PBEP86-NL double hybrid performs well enough to serve as a sec...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: RSC Advances
سال: 2015
ISSN: 2046-2069
DOI: 10.1039/c5ra20085g