F. Trouw

Measurement and Ab initio modeling of the inelastic neutron scattering of solid N-methylformamide.

Vibrational motions of solid N-methylformamide (NMF) and its N-deuterated analogue are investigated using the inelastic neutron scattering (INS) technique at 15 K. The force field for obtaining the normal vibrational modes of the crystal is based on a quantum chemical calculation and a subsequent transfer of a harmonic force field of a smaller pentameric segment to a fragment of 11 NMF molecules. Two types of hydrogen bonds present in crystalline NMF are also modeled with dimers. The distinct bonding leads to a splitting of the N-hydrogen wagging mode in the spectrum. Although the hydrogen bonding has a profound effect on vibrational frequencies, the results indicate that an occurrence of a double-well potential for bonded hydrogen proposed previously is unlikely. Instead, a limited electronic conjugation along the hydrogen bonds in crystalline NMF is observed. Unlike in previous models, we simulate the relative INS intensity of each vibrational transition separately, which leads to a substantial improvem...

Spin gap in a quasi-one-dimensional S = 1 2 antiferromagnet: Cu 2 ( 1 , 4 − d i a z a c y c l o h e p t a n e ) 2 Cl 4

Cu_{2}(1,4-diazacycloheptane)_{2}Cl_{4} contains double chains of spin 1/2 Cu^{2+} ions. We report ac susceptibility, specific heat, and inelastic neutron scattering measurements on this material. The magnetic susceptibility,

Crystal and magnetic structure of α-NiMoO4☆

\chi(T)

Properties of water in calcium- and hexadecyltrimethylammonium-exchanged bentonite

, shows a rounded maximum at T = 8 K indicative of a low dimensional antiferromagnet with no zero field magnetic phase transition. We compare the

Dynamics of methane trapped in C60 interstices

\chi(T)

Molecular dynamics simulation and inelastic neutron scattering

data to exact diagonalization results for various one dimensional spin Hamiltonians and find excellent agreement for a spin ladder with intra-rung coupling

Methane dynamics in the 36 Å mesopores of MCM-41 studied by neutron scattering

J_1 = 1.143(3)

OBSERVATION OF BOSON PEAKS BY INELASTIC NEUTRON SCATTERING IN POLYOLEFINS

meV and two mutually frustrating inter-rung interactions:

Methane dynamics in porous xerogels characterized by small-angle and quasielastic neutron scattering

J_2 = 0.21(3)

Neutron inelastic scattering studies of UF4 and NpF4

meV and