Software Compatibility

Critic2 can read structures and scalar fields from multiple sources. The amount of information available to critic2 depends on the source file. The table below gives the computational chemistry software with which critic2 can interface, listed in alphabetical order.

The file format is assumed by critic2 based on the extension (although there are keywords to change this behavior). The table gives in the second column the extensions critic2 uses for each format. When the same extension is used for different formats, critic2 will try to guess the correct format from the contents of the file.

The “structures” column gives whether the structure of a molecule, a crystal, or both can be read from the file. A crystal structure must be read with the CRYSTAL keyword and a molecule with the MOLECULE keyword.

The “fields” column gives the information read by critic2 when this file is read as a new scalar field using the LOAD keyword. In this column, “grid” means that the field is available only at the points belonging to a uniform grid, and that the value calculated at any other point is obtained by interpolation. “arbitrary” means that the scalar field read corresponds to whatever the program generated; critic2 will make no assumptions. “rho” means that the electron density is read, and “wfn” means that the wavefunction is read. The latter typically allows calculating values of individual molecular orbitals, energy densities, and other quantities. “basis” means that the basis set is read, which enables the calculation of molecular integrals.

More details about these formats can be found in the documentation for the CRYSTAL, MOLECULE, and LOAD keywords.

Software Format (extension) Structures Fields Notes
Multiple cif crystals    
  cube crystals,molecules grid,arbitrary  
  bincube crystals,molecules grid,arbitrary Binary version of a cube file, generated by critic2
  xyz molecules   Number of atoms in line 1; line 2 ignored
  mol2 molecules    
  pdb molecules   Used in biochemical applications
abinit DEN,PAWDEN,ELF,POT,etc. crystals grid,arbitrary  
ADF molden molecules rho,wfn,basis  
aimpac qub   grid,arbitrary  
aiPI ion crystals rho  
CASTEP cell crystals   CASTEP input file
  geom crystals   CASTEP output file
  fmt   grid,arbitrary Generated by CASTEP write_* keywords
Crystal17 out crystals   Crystal17’s output file
DFTB+ gen crystals,molecules    
  xml crystals,molecules rho,wfn DFTB+’s detailed.xml file (plus bin and hsd)
DMACRYS dmain crystals   The DMACRYS main input file
  16 crystals   fort.16 file generated by DMACRYS
  21 crystals   fort.21 file generated by NEIGHCRYS
elk OUT crystals   Elk’s GEOMETRY.OUT file
  grid crystals grid,arbitrary Requires a patch to the elk source code
  OUT crystals rho,arbitrary Elk’s STATE.OUT,etc.
FHIaims in,in.next_step crystals,molecules   FHIaims and
  out,own crystals,molecules   FHIaims output file
Gaussian cube molecules grid,arbitrary  
  wfn,wfx molecules rho,wfn  
  fchk molecules rho,wfn,basis  
  log molecules   Gaussian output file
  gjf,com molecules   Gaussian input file
  zmat molecules   z-matrix format
ORCA molden,molden.input molecules rho,wfn,basis  
postg pgout molecules   postg output file
psi4 molden molecules rho,wfn,basis  
  fchk molecules rho,wfn,basis  
  dat molecules   psi4 output file
Quantum ESPRESSO out, pwo crystals   pw.x output file (typically .scf.out or .pwo)
  in, pwi crystals   pw.x input file (typically or .pwi)
  cube crystals grid,arbitrary Generated by pp.x
  pwc crystals grid,rho,wfn Generated by pw2critic.x
SHELX res crystals    
  ins crystals   Same format as a res file
SIESTA STRUCT_IN,STRUCT_OUT crystals   Input and output structure files
  RHO,BADER,DRHO,LDOS,VT,VH crystals grid,arbitrary Do not contain information about the structure
TINKER frac crystals    
VASP POSCAR,CONTCAR,vasp crystals    
  CHGCAR,CHG,ELFCAR,AECCAR* crystals grid,arbitrary  
WIEN2k struct crystals    
  clmsum,clmup,clmdn crystals rho,arbitrary  
Xcrysden xsf,axsf crystals grid,arbitrary