critic2 – Our “swiss army” software tool. Use this for:

  • converting between file formats and writing input for electronic structure codes starting from molecular or crystal geometries (.cif, .res, .xyz)
  • extracting single molecules, dimers, trimers, etc. from a crystal structure
  • comparing crystal structures with each other, and with experimental PXRD patterns
  • operations on cube files and plotting results on a line or plane
  • QTAIM analysis, including Bader charges and delocalization indices
  • much more

Also, see here VC-PWDF_Manual-v2.pdf for a manual describing the use of our variable-cell powder difference (VC-PWDF) method within critic2, along with a script for plotting overlays of simulated and experimental PXRD patterns.

postg – Allows use of the XDM dispersion model with the Gaussian quantum-chemistry package.

nciplot – Allows generation of NCI and ELF cube files from a wavefunction (.wfn, .wfx) file.

escher – A set of octave routines for generating pretty images of molecular and crystal structures.

bicrystal – Use this to build incommensurate structures of layered materials.

Reference data for selected benchmark sets can be found here: refdata

XDM damping parameters for use with selected electronic structure packages can be found in the postg distribution. A subset of these is shown here:


Functional Basis a1 a2 (Å)
B86bPBE PAW 0.6512 1.4633
PBE PAW 0.3275 2.7673


Functional Basis a1 a2 (Å)
PBE light 0.5312 2.3270
B86bPBE light 0.8219 1.2069
PBE0 light 0.3302 3.0042
B86bPBE-25 light 0.5235 2.1995
B86bPBE-50 light 0.0831 3.7362
PBE tight 0.6438 1.8533
B86bPBE tight 0.8976 0.8518
PBE0 tight 0.5053 2.2527
B86bPBE-25 tight 0.6546 1.6097
B86bPBE-50 tight 0.4887 2.1855


Functional Basis a1 a2 (Å)
PBE0 aug-cc-pVTZ 0.4186 2.6791
B3LYP aug-cc-pVTZ 0.6356 1.5119
LC-wPBE aug-cc-pVTZ 1.0149 0.6755
B3LYP 6-311+G(2d,2p) 0.4376 2.1607
LC-wPBE 6-311+G(2d,2p) 0.5313 2.2665
B3LYP Mixed DZ 0.0000 3.7737
LC-wPBE Mixed DZ 0.6889 1.9452

Mixed DZ indicates 6-31G* for H, B, C, and Si and 6-31+G* for all other elements.