# Tail correction for crystals.

1. Dec 25, 2009

### aihaike

Hi all,

I'm doing classical (Monte Carlo) simulations on crystal structures using so far the following tail correction where $$\rho(r)$$ is the pair correlation function and $$U(r)$$ the pair potential.

$$2N\pi\rho\int_{r_{c}}^{\infty}\mathrm{d}r\, r^{2}U(r)$$

It is usual to assume that $$\rho(r)=1$$ for $$r>=r_{c}$$.

I'm wondering if this approximation is suitable for crystals.
For fcc and hcp Lennard Jones systems, lattice sum has been implemented (J. Chem. Phys., Vol. 115, No. 11 ; J. O. Hirschfelder, C. F. Curtiss, and R. B. Bird, Molecular Theory of Gases and Liquids, Wiley, New York, 1954, pp. 1036–1039) and I'd like to know if there is a general approach to apply it to any crystal structure.
Martin Dove talks about that as well in his book "Introduction to Lattice Dynamics" but he uses a kind of Ewald summation and I'd prefer to use the same approach as for the Lennard Jonesium.