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Title: Excited States of DNA Base Pairs Using Long-Range Corrected Time-Dependent Density Functional Theory

In this work we present a study of the excitation energies of adenine, cytosine, guanine, thymine and the adenine-thymine (AT) and guanine-cytosine (GC) base pairs using long-range corrected (LC) density functional theory. We compare three recent LC-functionals, BNL, CAM-B3LYP and LC-PBE0 with B3LYP and coupled cluster results from the literature. We find that the best overall performance is for the BNL functional based on LDA. However, in order to achieve this good agreement a smaller attenuation parameter was needed which leads to non-optimum performance for ground state properties. B3LYP, on the other hand, severely underestimates the charge transfer (CT) transitions in the base pairs. Surprisingly we also find that the CAM-B3LYP functional also underestimates the CT excitation energy for the GC base pair, but correctly describes the AT base pair. This illustrates the importance of retaining the full long-range exact exchange even at distances as short as that of the DNA base pairs. The worst overall performance was obtained with the LC-PBE0 functional which overestimates the excitations for the individual bases as well as the base pairs. It is therefore crucial to strike a good balance between the amount of local and long-range exact exchange.
Authors:
;
Publication Date:
OSTI Identifier:
965549
Report Number(s):
PNNL-SA-67112
29790; KP1504020; TRN: US200919%%622
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry A, 113(36):9761-9765; Journal Volume: 113; Journal Issue: 36
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; ATTENUATION; CYTOSINE; DNA; EXCITATION; EXCITED STATES; FUNCTIONALS; GROUND STATES; GUANINE; PERFORMANCE; THYMINE; time-dependent density functional theory; excitation; energies; Environmental Molecular Sciences Laboratory