TY - JOUR
T1 - Charge ordering and the structure of ionic liquids
T2 - Screened Coulomb versus Coulomb interionic potentials
AU - Copestake, A. P.
AU - Evans, Robert
PY - 1982
Y1 - 1982
N2 - The authors have calculated the radial distribution functions g
alpha beta(r) and the partial structure factors S
alpha beta(k) for two different charged hard-sphere models of a molten alkali halide. In the first model the interionic potentials are taken to be Coulombic outside the hard core; this is the conventional restricted primitive model. In the second the potentials are assumed to be screened Coulomb outside the core. Their calculations, which are based on the mean spherical approximation and on the hypernetted-chain approximation, demonstrate that very short-ranged screened potentials can produce g
alpha beta(r) and S
alpha beta(k) which are very close to those obtained for the conventional restricted primitive model of an alkali halide. In particular, the distribution functions for the screened Coulomb model exhibit 'charge ordering'; g
++(r) oscillates out of phase with g
+-(r) and the first peak in S
++(k) lines up with the first minimum in S
+-(k). 'Charge ordering' is not a unique feature of Coulombic interactions as is sometimes supposed, but will occur whenever the potential between unlike species is strongly attractive.
AB - The authors have calculated the radial distribution functions g
alpha beta(r) and the partial structure factors S
alpha beta(k) for two different charged hard-sphere models of a molten alkali halide. In the first model the interionic potentials are taken to be Coulombic outside the hard core; this is the conventional restricted primitive model. In the second the potentials are assumed to be screened Coulomb outside the core. Their calculations, which are based on the mean spherical approximation and on the hypernetted-chain approximation, demonstrate that very short-ranged screened potentials can produce g
alpha beta(r) and S
alpha beta(k) which are very close to those obtained for the conventional restricted primitive model of an alkali halide. In particular, the distribution functions for the screened Coulomb model exhibit 'charge ordering'; g
++(r) oscillates out of phase with g
+-(r) and the first peak in S
++(k) lines up with the first minimum in S
+-(k). 'Charge ordering' is not a unique feature of Coulombic interactions as is sometimes supposed, but will occur whenever the potential between unlike species is strongly attractive.
UR - http://www.scopus.com/inward/record.url?scp=34548561715&partnerID=8YFLogxK
U2 - 10.1088/0022-3719/15/24/009
DO - 10.1088/0022-3719/15/24/009
M3 - Article (Academic Journal)
AN - SCOPUS:34548561715
SN - 0022-3719
VL - 15
SP - 4961
EP - 4974
JO - Journal of Physics C (Solid State Physics)
JF - Journal of Physics C (Solid State Physics)
IS - 24
M1 - 009
ER -