TY - JOUR
T1 - Ab initio calculations and INS measurements of phonons and molecular vibrations in a model peptide compound - Urea
AU - Johnson, M. R.
AU - Parlinski, K.
AU - Natkaniec, I.
AU - Hudson, B. S.
N1 - Funding Information:
The authors are grateful to Ron Ghosh for support with computational facilities at ILL and to the CGCV at the Centre d’Etudes Atomique Grenoble for access to supercomputing facilities. Support from the State Committee of Scientific Research (KBN), Grant No. 5 PO3B 069 20 and the US Department of Energy Grant DE-FG02-01-ER-152 is acknowledged. The Rutheroford Appleton Laboratory is thanked for access to neutron beam facilities at the ISIS facility.
PY - 2003/6/1
Y1 - 2003/6/1
N2 - Density functional theory (DFT) methods, as implemented in the VASP code, are used to calculate the inelastic neutron scattering (INS) spectrum of urea, which has been measured on the TOSCA spectrometer at ISIS, UK and the NERA-PR spectrometer at Dubna, Russia. Urea presents an extended network of bifurcated hydrogen bonds resulting in significant dispersion of the vibrational excitations, both for external and internal modes. The small mass of the molecule also results in intense multiphonon contributions to the spectral profile. Recent, successful applications of DFT in molecular spectroscopy are extended here using the PHONON code to include dispersion and multiphonon contributions to the INS spectrum. Thus the whole spectral profile is calculated with only the crystal structure as input. The accuracy of the calculated normal modes is demonstrated for protonated and deuterated urea.
AB - Density functional theory (DFT) methods, as implemented in the VASP code, are used to calculate the inelastic neutron scattering (INS) spectrum of urea, which has been measured on the TOSCA spectrometer at ISIS, UK and the NERA-PR spectrometer at Dubna, Russia. Urea presents an extended network of bifurcated hydrogen bonds resulting in significant dispersion of the vibrational excitations, both for external and internal modes. The small mass of the molecule also results in intense multiphonon contributions to the spectral profile. Recent, successful applications of DFT in molecular spectroscopy are extended here using the PHONON code to include dispersion and multiphonon contributions to the INS spectrum. Thus the whole spectral profile is calculated with only the crystal structure as input. The accuracy of the calculated normal modes is demonstrated for protonated and deuterated urea.
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U2 - 10.1016/S0301-0104(03)00178-2
DO - 10.1016/S0301-0104(03)00178-2
M3 - Article
AN - SCOPUS:0038353930
SN - 0301-0104
VL - 291
SP - 53
EP - 60
JO - Chemical Physics
JF - Chemical Physics
IS - 1
ER -