The Computational Materials Repository

2.8 What is actually stored in a db-file? 45gpaw, vasp, gaussian or dacapo. db date stores the creation date of the db-filewhile db last modified the one of the last applied modification. The uniqueidentifier is store in the field db hash and the user name in db user. db locationshould be filled with the department and is defined when installing CMR. Themore interesting field are the description (db description), a list of keywords(db keywords), the names of the attached scripts (db scripts) and of other files(db files).For programs like gpaw and dacapo and as well ASE trajectory files theinformation that ASE provides is extracted and added as fields. The advantageof using them is that it we know that the units are always in eV and Angstrom.The extracted ASE information from the calculation of a N2 molecule is shownin Fig. 2.24. This information belonging to each atom is interpreted by aligningthe arrays: Fig. 2.25.ase atomic numbers [7, 7]ase cell [[1.0, 0.0, 0.0], [0.0, 1.0...ase center of mass [0.0, 0.0, 0.0]ase charges [0.0, 0.0]ase chemical symbols [’N’, ’N’]ase forces [[0.0, 0.0, -0.005629824829...ase initial magnetic moments [0.0, 0.0]ase kinetic energy 0.0ase masses [14.0067, 14.0067]ase momenta [[0.0, 0.0, 0.0], [0.0, 0.0...ase moments of inertia [6.9777930978192266, 6.9777...ase nameN2ase number of atoms 2ase pbc[False, False, False]ase positions [[0.0, 0.0, 0.4990868562675...ase potential energy 0.262777484094ase reciprocal cell [[1.0, 0.0, 0.0], [0.0, 1.0...ase scaled positions [[0.0, 0.0, 0.4990868562675...ase tags [0, 0]ase temperature 0.0ase total energy 0.262777484094ase volume 1.0Figure 2.24: These fields that are extracted with ASE and added to the db-files, if theprogram supports ASE.The easiest was to read this information is actually to open the db-file withase directly and use view e.g.from ase . i o import readfrom ase . v i s u a l i z e import viewdata = read ( ’ N2 . db ’ )