DL POLY

DL_POLY is a general purpose serial and parallel molecular dynamics simulation package developed at Daresbury Laboratory by W. Smith, T.R. Forester and I.T. Todorov. DL_POLY employs an interesting set of units which have molecular relevance:

physical quantity	symbol	unit value
time	$t_{0}$	$1\times 10^{-12}$ seconds (picoseconds)
length	$l_{0}$	$1\times 10^{-10}$ metres (Angstroms)
mass	$m_{0}$	$1.66054\times 10^{-27}$ kilograms (amu)
charge	$q_{0}$	$1.60218\times 10^{-19}$ Coulombs (electron charge)
energy	$E_{0}=m_{0}(l_{0}/t_{0})^{2}$	$1.66054\times 10^{-23}$ Joules = 10 J mol$^{-1}$
pressure	$p_{0}=E_{0}/l_{0}^{3}$	$1.66054\times 10^{7}$ Pascal = 166.054 bar
Planck constant	$\hbar$	$6.35078E_{0}t_{0}$
Boltzmann constant	$k_{B}$	$0.83145E_{0}/K$

References

1. W. Smith, C. W. Yong and P. M. Rodger "DL_POLY: application to molecular simulation", Molecular Simulation 28 pp. 385-471 (2002)