- Write the energy per atom (or per unit cell of the lattice) in the */energy files. One should write the
energy per unit cell of the structure (that is, in the way a first-principles code usually gives it).
- Errors in the lat.in file. Use the corrdump -sym ; more sym.out command to analyse the symmetry of the
lattice and see if it correspond to your expectations. You can also use corrdump -2=10 -clus ; more clusters.out to
verify the symmetrically distrinct pairs are what you expect them to be.
- When the structures are not generated by MAPS (i.e. you typed them it), beware of typos.
MAPS will detect if a structure is incompatible with the lattice but it will not detect another
very common mistake: putting the energy and str.out files that correspond to different structures
in the same directory. To check for this error, look at the residual plot generated by mapsrep.
- When copying the lat.in files provided as examples, make sure you make all the required changes.
(i) Change the atom names. (ii) Set the lattice parameters (first 3 numbers in the file) to values that are
at least as large as the true lattice parameter (otherwise, first-principles code can be unable to properly
relax the geometry of the structure is the atoms are too close to one another initially).
avdw@alum.mit.edu Wed, Dec 6, 2023 12:55:16 PM