calc of dielectric const.

[wsonnen "-at-" alnitak.usc.edu (Wayne Sonnen)]

 Monica,
 with respect to your question about calculation of dielectric constants
 using MD....
 It is not clear to me at what level you wish to calculate dielectric
 constant (i mean dielectric permittivity). From an MD calculation, i
 see two levels: with and w/o polarizabilities in the water model.
 Regardless of the water model, you can use equation 5.25 in Allen
 and Tildesley's book. Page 163, second last paragraph, states the
 importance of the external relative permittivity. There should be
 sufficient references in this book.
 Additional references on water models (i have lots of them) are:
 (1) H.J.C. Berendsen, JPC (1987) {\bf 91}, 6269-6271
 (2) W.L. Jorgensen, JCP (1983) {\bf 79}, 926-935
 (3) U. Niesar, ACS (1990) {\bf 94}, 7949-7956
 (4) P. Ahlstrom, Mol Phys (1989), {\bf 68} 563-581
 (5) A. Rahman, JCP (1971), {\bf 55}, 3336-3359
 (6) D. L. Beveridge, In: 'Molecular-Based Study of Fluids', Chapter 13.
     (1982 ??). (sorry, i don't have a complete ref.; editor ??).
 Ref. #(5), equation 4.15 discusses the calculation of 'dielectric constant'
 from MD simulation. The equation may appear to be complicated, but this
 particular equation simply uses the static dipole moment of water (about
 1.85 D) and two calculated quantities from the simulation: the polarizability
 and the (permanent dipole) orientational correlation function.
 good luck,
 Wayne Sonnen