CANDELA is short for Collection of ANalysis DEsigned for Large-scale Atomic simulations. It is developed by MCresearch to conduct analyses on MD trajectory in different formats. Right now the program only supports analysis of pair distribution function (PDF), static structure factor (SSF) and mean square displacement (MSD). The minimum supported version of ABACUS is 3.2.0.

Requirements for using CANDELA

For Detailed usage of CANDELA, please refer to the official document. There are two things which need special attention in using CANDELA with ABACUS. First, the input file of CANDELA only takes the name of INPUT, the same as ABACUS input file, so you should not run CANDELA in the same folder where you run ABACUS. Second, to use CANDELA to postprocess ABACUS MD trajectory, the following parameters have to be specified in the INPUT file of CANDELA in addition to other required parameters:

  1. geo_in_type has to be set to ABACUS;

  2. msd_dt has to be specified in unit of picosecond, especially in the case of calculation = msd;

  3. geo_directory has to be set to the path to the MD_dump file in the folder. As a result, a CANDELA INPUT file for calculating PDF from ABACUS should be something like this:

calculation  pdf # Pair Distribution Function.
system Al
geo_in_type  LAMMPS
geo_directory ../geo/Al64.dump
geo_1        0
geo_2        20
geo_interval 1
geo_ignore   4

geo_out      pdf.txt # output pdf name.

ntype        1        # number of different types of atoms.
natom        64   # total number of atoms.
natom1       64
rcut         6
dr           0.01     # delta r in real space

struf_dgx   0.05
struf_ng    200

More examples of CANDELA INPUT with ABACUS can be found in the test directory.