Electrostatic considerations affecting the calculated HOMO-LUMO gap in protein molecules

التفاصيل البيبلوغرافية
العنوان: Electrostatic considerations affecting the calculated HOMO-LUMO gap in protein molecules
المؤلفون: Lever, Greg, Cole, Daniel J, Hine, Nicholas D M, Haynes, Peter D, Payne, Mike C
سنة النشر: 2013
المجموعة: Condensed Matter
Physics (Other)
Quantitative Biology
مصطلحات موضوعية: Physics - Chemical Physics, Condensed Matter - Soft Condensed Matter, Quantitative Biology - Biomolecules
الوصف: A detailed study of energy differences between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO gaps) in protein systems and water clusters is presented. Recent work questioning the applicability of Kohn-Sham density-functional theory to proteins and large water clusters (E. Rudberg, J. Phys.: Condens. Mat. 2012, 24, 072202) has demonstrated vanishing HOMO-LUMO gaps for these systems, which is generally attributed to the treatment of exchange in the functional used. The present work shows that the vanishing gap is, in fact, an electrostatic artefact of the method used to prepare the system. Practical solutions for ensuring the gap is maintained when the system size is increased are demonstrated. This work has important implications for the use of large-scale density-functional theory in biomolecular systems, particularly in the simulation of photoemission, optical absorption and electronic transport, all of which depend critically on differences between energies of molecular orbitals.
Comment: 13 pages, 4 figures
نوع الوثيقة: Working Paper
DOI: 10.1088/0953-8984/25/15/152101
URL الوصول: http://arxiv.org/abs/1302.4696
رقم الأكسشن: edsarx.1302.4696
قاعدة البيانات: arXiv
الوصف
DOI:10.1088/0953-8984/25/15/152101