Control and Prediction of the Organic Solid State

System Requirements and Compiler issues

Please check our recommendations for the computer system and compilers.

Known problems with DMAREL

d packing types from MOLPAK have density out by a factor of 2.

Known problems with previous release version (1.11) of DMACRYS

There are some problems with symmetry reduction.
DMACRYS does not work for spherical ions (eg Cl^-).

Known problems with previous release version (1.10) of NEIGHCRYS

It standardises all OH bond lengths to 0.976 Å (neutron value from Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen, A. G.; Taylor, R. Tables of bond lengths determined by x-ray and neutron diffraction. Part 1. Bond lengths in Organic compounds. Journal of the Chemical Society-Perkin Transactions 2 1987, (12), S1-S19.), which is not appropriate for carboxylic acids or water.
An extra line, reporting the number of times the primitive cell appears in the unit cell, was introduced, for use with DMAflex2
NEIGHCRYS assigns S as silicon for .fdat files, although .res files it is correctly assigned as sulfur.

Current release versions

DMACRYS version 2.0.2 and NEIGHCRYS version 2.0.2

These versions of the codes have been developed to deal with spherical ions, and so are not compatible with version 1.

Please email Louise if there is anything you want to add to this page. If you spot a new problem, let her know, or if you have anything further to add to an existing problem. Also, if you have solved the problem, email Louise to remove it from the list.

Targets for new development version DMACRYS 2.1.0 and NEIGHCRYS 2.1.0

Addition of splines to smooth off potential at cutoff distances, and hence give better numerical derivatives with moderate cutoffs
Inclusion of induction energy using distributed dipolar polarisability models
Include (damped) C6 C8 and C10 isotropic dispersion
Ensure linear molecules can be used
Ensure P3 space groups work

Known limitations of programs

NEIGHCRYS copes with only some Z'<1 input files.
Automated symmetry reduction is not possible with custom potentials (particularly for anisotropic repulsion), because of the need to generate the atoms typing and local axes for the new independent molecule in the asymmetric unit cell.
Only one Tang-Toennies damping parameter can be specified for the entire molecule.

Enter secure pages (For project members only - password required)

Warning: This page uses Cascading Style Sheets. We recommend you upgrade to a current version of your favourite browser.