Following file types are recognized:

- fhi, fly, gau, lam, mop, mpr, tin, vas – FHI-aims, GAMESS Firefly, Gaussian, LAMMPS, MOPAC, Molpro, TINKER or VASP input file
- out – (text) program-specific output file
- xyz,cif – (text) atomic coordinates
- coo – (binary) atomic coordinates ::Matrix(3,na)
- md – (binary) MD trajectory or set of configurations ::Array(3,na,nconf)
- mdm – (binary) same as 'md' but grouped into molecules ::Array(3,na,nm,nconf)
- mgf – (text) file containing MO/NO/NTO for visualization
- pes – (binary) potential energy surface data
- frcc – (binary) force constants ::Matrix(3*na,symmetric)
- evl, evla, evlb – (binary) eigenvalues, alpha- and beta-eigenvalues ::Vector(no)
- evc, evca, evcb – (binary) eigenvectors ::Matrix(N,no)
- evr – (binary) bra-eigenvectors = Transpose(evc)*s1e ::Matrix(no,N)
- s1e – (binary) overlap matrix ::Matrix(N,symmetric)
- h1e – (binary) one-electron Hamiltonian ::Matrix(N,symmetric)
- rho, rhoa, rhob – (binary) density matrix ::Matrix(N,symmetric)
- 633 – (binary) Gaussian record 633

* Symmetric matrices are written as triangular[lower]