Editing DL POLY

[http://www.cse.clrc.ac.uk/ccg/software/DL_POLY/index.shtml 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 <ref>[http://dx.doi.org/10.1016/S0263-7855(96)00043-4  W. Smith and T. R. Forester "DL_POLY_2.0: A general-purpose parallel molecular dynamics simulation package", Journal of Molecular Graphics   '''14''' pp. 136-141 (1996)]</ref>
<ref>[http://dx.doi.org/10.1080/08927020290018769 W. Smith,  C. W. Yong and P. M. Rodger "DL_POLY: application to molecular simulation", Molecular Simulation '''28''' pp. 385-471 (2002)]</ref>
==Units==
DL_POLY employs an interesting set of units which have molecular relevance:
{| border="1"
|- 
| physical quantity || symbol || unit value
|-  
| time   || <math>t_0 </math>  || <math>1\times10^{-12} </math> seconds (picoseconds)
|-
| length || <math>l_0 </math>|| <math>1\times10^{-10} </math> metres (Angstroms)
|-
| mass   || <math>m_0 </math>|| <math>1.66054\times10^{-27} </math> kilograms ([[Atomic mass units|amu]])
|-
| charge || <math>q_0 </math>|| <math>1.60218\times10^{-19} </math> Coulombs (electron charge)
|-
| energy || <math>E_0=m_0(l_0/t_0)^2 </math>|| <math>1.66054\times10^{-23} </math> Joules = 10 J mol<math>^{-1}</math>
|-
| [[pressure]] || <math>p_0=E_0/l_0^3 </math>|| <math>1.66054\times10^{7} </math> Pascal = 166.054 bar
|-
| [[Planck constant]] || <math>\hbar</math>|| <math>6.35078 E_0 t_0 </math>
|-
| [[Boltzmann constant]] || <math>k_B</math>|| <math>0.83145 E_0/K </math>
|}
==Force field==
The [[force fields | force field]] used in DL_POLY consists (or can consist) of the following components:
*Chemical bond potentials:
**[[Harmonic bond potential]]
**[[Morse potential]]
**[[Lennard-Jones model | Lennard-Jones 12-6]]
**[[Restraint bond potential]]
**[[Quartic bond potential]]
**[[Buckingham potential]]
**[[FENE potential]]
*Angles:
**[[Harmonic angle potential]]
**[[Quartic angle potential]]
**[[Truncated harmonic angle potential]]
**[[Screened harmonic angle potential]]
**[[Screened Vessal angle potential]]
**[[Truncated Vessal angle potential]]
**[[Harmonic cosine angle potential]]
**[[Cosine angle potential]]
**[[MM stretch-bend angle potential]]
**[[COMPASS stretch-stretch]]
**[[COMPASS stretch-bend]]
**[[COMPASS all terms]]
*Dihedral angles:
**[[Cosine dihedral angle potential]]
**[[Harmonic dihedral angle potential]]
**[[Harmonic cosine dihedral angle potential]]
**[[Triple cosine dihedral angle potential]]
**[[Ryckaert-Bellemans dihedral angle potential]]
***[[Flourinated Ryckaert-Bellemans dihedral angle potential]]
**[[OPLS | OPLS dihedral angle potential]]
*Inversion angle potentials:
**[[Harmonic inversion angle potential]]
**[[Harmonic inversion angle potential]]
**[[Planar inversion angle potential]]
==Versions of DL_POLY==
====DL_POLY_2====
DL_POLY_2 was designed for simulations of up to 30,000 atoms and on parallel computers using up to 100 processors.
====DL_POLY_3====
DL_POLY_3 was designed for simulations of order 100,000 to 1,000,000 atoms running on up to 1000 processors. 
*DL_POLY_3 does not handle rigid body molecules.
====DL_POLY_4====
The first DL_POLY_4 release is expected early in 2010.
====DL_MULTI====
A DL_POLY package to simulate rigid molecules with multipoles.
*[http://dx.doi.org/10.1080/00268970802175308 M. Leslie "DL_MULTI—A molecular dynamics program to use distributed multipole electrostatic models to simulate the dynamics of organic crystals", Molecular Physics '''106''' pp. 1567-1578 (2008)] 
==Visualising DL_POLY output==
The visualisation program [[VMD]] is capable of displaying the HISTORY trajectory file. 
==References==
<references/>
==External links==
*[http://www.cse.scitech.ac.uk/ccg/software/DL_POLY/MANUALS/USRMAN2.20.pdf DL_POLY_2.20 User Manual (PDF)]
*[http://www.cse.scitech.ac.uk/ccg/software/DL_POLY/MANUALS/USRMAN3.10.pdf DL_POLY_3.10 User Manual (PDF)]

[[Category: Materials modelling and computer simulation codes]]