CCL:G: improved code for atomic population analysis



Hi all,

If you are currently using or have previously tried earlier versions of the Chargemol program to compute Density Derived Electrostatic and Chemical (DDEC) net atomic charges, atomic spin moments, or bond orders, I strongly recommend downloading and using Version 3.4, released on December 31 2015, that provides important improvements over previous versions.

This version introduces a new charge partitioning algorithm, called DDEC6, that is described in a recent arXiv preprint (http://arxiv.org/abs/1512.08270) and will be published in forthcoming journal articles. The DDEC6 algorithm improves accuracy, reduces computational time, and converges robustly to a unique solution. I strongly recommend its use for all kinds of chemical systems.

As far as I am aware, this is the only widely available code that facilitates easy computation of bond orders from VASP files. It also works with wfx files generated by Gaussian 09 or other quantum chemistry programs. Some lesser used file formats can also be read.

The new version can be downloaded for free from ddec.sourceforge.net and works on linux and windows platforms. The Fortran version is parallelized with openMP and exhibits good parallelization efficiency for multiple processors on a single compute node. The parallelization routines for Version 3.4 include critical improvements over the earlier versions. Accuracy and convergence reliability are vastly improved along with substantial reductions in computational cost.

Sincerely,

Tom Manz
assistant professor
Chemical & Materials Engineering Department
New Mexico State University