4.1. GENERAL STRATEGIES

next, previous Section / Table of Contents / Index In all sessions: - After you have created a structure from scratch always store it on an output file for use in subsequent sessions. Even the weirdest structure can be useful later on. - In 3-dimensional views always use central projection. Otherwise, the structure may look distorted. - Make use of the wire frame option to obtain a good visual impression of the structure orientation. Resetting the view focus and/or hiding atoms helps to see fine details in a lattice or cluster. - Do not use complex graphics output (e.g. shaded balls) in the beginning of the analysis when fast plotting is needed. - Make extensive use of the graphical analysis option to orient yourself in a complex lattice or cluster. - When trying to get the full color stereo impression by squinting relax your eyes from time to time to avoid feeling dizzy. - In viewing structures use the stack option and the picture import/ export options to save intermediate views. - If special color assignments are included in your structure store the structures always with the init flag set to "on" (file output menu). Otherwise all color reassignments will be lost and defaults will be applied in subsequent session using your file as input. - Use the help option (press [?]+[x] to obtain help on option [x]) whenever you need to be reminded what an option does before you use it. - In Unix systems using the mouse menu option with menu windows is more explicit than using option keys only. In BALSAC/LATTICE sessions: - Try to start from a similar lattice section or cluster structure defined by an input file rather than building a structure from scratch. This saves time. - In an interactive graphical application with uncommon lattice geometry always start with small sections of a few parallel lattice planes until you have some orientation. - Use enough parallel lattice planes to get a full impression of the lattice. Reduce atomic radii or use the dot option to make the plot look less busy. Always experiment with different viewing directions, magnifications, and perspectives. View along or near a crystallographic or high symmetry direction (such as in the initial orientation). Make also use of the stereo and the connect atoms features. - Lattice sections of closed packed crystals (fcc, hcp,...) of high Miller index planes may require many lattice planes to show a closed structure. - Lattice sections where the lengths of basis vectors differ considerably may require quite different numbers of atoms in each lattice direction to achieve reasonable section sizes. - Be very careful in using option flags (the maximum number is 48) in input files for BALSAC/LATTICE batch runs. The program and you can get confused if incorrect parameter values are supplied with one option followed by another option in batch mode. Batch mode always assumes that you supply the correct number of meaningful parameter values. So check option flags in BALSAC/LATTICE input files twice before you use the files. - In complex lattices with many atoms/ions the maximum number of atoms included in one plot of a BALSAC/LATTICE session is limited by the internal sorting process before plotting where the internal maximum is set to 2001 (DOS) or 8000 (Unix) atoms. In layer-by-layer graphics mode this maximum applies only to the atoms of each layer. This allows you to display larger lattice sections than for atom-by-atom or cell-by-cell graphics mode where the maximum refers to all atoms of the plot, see also Sec. 6.2.7. - Save BALSAC/LATTICE structures in extended LATUSE format files only if atom coordinates are really needed for external analysis or in applications outside BALSAC. Extended LATUSE format output files are larger in size than respective PLOT3D format files and may become very large. In BALSAC/CLUSTER sessions: - In clusters with symmetry you can construct the system faster if you first build the irreducible part and then apply global symmetry constraints such as rotation axes or mirror planes (symmetry options structure menu). - Use the group manipulation options to build the clusters. Store small molecular subsystems on files for further use. - In complex clusters with many atoms/ions you can group atoms visually by assigning them the same nuclear charges (thus color). next, previous Section / Table of Contents / Index