Get a license for CALYPSO by going to this page and filling out the form.

Then download the latest CALYPSO package as well as the manual.

Install CALYPSO on your Linux/Mac machine using the instructions from the manual.

Make sure that Quantum ESPRESSO is installed and working correctly. Also make sure that you have the correct address to the ‘pw.x’ executable binary.

Now we can begin with the nanocluster global optimization.

You need to create 3 files.

First is the input.dat for CALYPSO. This should look like the following:

################################ The Basic Parameters of CALYPSO ################################ # A string of one or several words contain a descriptive name of the system (max. 40 characters). SystemName = Z # Number of different atomic species in the simulation. NumberOfSpecies = 2 # Element symbols of the different chemical species. NameOfAtoms = Zn S # Number of atoms for each chemical species in one formula unit. NumberOfAtoms = 3 3 # The range of formula unit per cell in your simulation. NumberOfFormula = 1 1 # The volume per formula unit. Unit is in angstrom^3. #Volume=60.0 # Minimal distance between atoms of each chemical species. Unit is in angstrom. @DistanceOfIon 1.0 1.0 1.0 1.0 @End # It determines which algorithm should be adopted in the simulation. Ialgo = 2 # Ialgo = 1 for Global PSO # Ialgo = 2 for Local PSO (default value) # The proportion of the structures generated by PSO. PsoRatio = 0.8 # The population size. Normally, it has a larger number for larger systems. PopSize = 30 # It determines which local optimization method should be interfaced in the simulation. ICode= 4 # ICode= 1 interfaced with VASP # ICode= 2 interfaced with SIESTA # ICode= 3 interfaced with GULP # The number of lbest for local PSO NumberOfLbest=4 # The Number of local optimization for each structure. NumberOfLocalOptim= 1 # The precision of the K-point sampling for local optimization Kgrid = 1 1 # The command to perform local optimiztion calculation (e.g., VASP, SIESTA) on your computer. Command = sh submit.sh # The Max step for iteration MaxStep =50 # If True, the metropolis rule is used during iterations LMC= T #########################End Basic Parameters ################### ###### The Parameters For Cluster structure prediction ######### # If True, a cluster structure prediction is performed. Cluster= T # The Vacancy length for 3 diminsional space Vacancy = 15 15 15 ####################End Cluster Parameters #######################

A file called ‘pw_input’ for Quantum ESPRESSO input.

&CONTROL calculation = "relax" forc_conv_thr = 3.88938e-04 max_seconds = 6.22080e+08 nstep = 100 pseudo_dir = "/home/dmishra_du/Pseudopotentials/" outdir="temp" tprnfor = .TRUE. tstress = .TRUE. / &SYSTEM celldm(1) = 1 ! a = 2.00000e+01 degauss = 1.00000e-02 ecutrho = 4.40000e+02 ecutwfc = 5.50000e+01 ibrav = 0 nat = 6 nbnd = 50 ntyp = 2 occupations = "fixed" smearing = "gaussian" / &ELECTRONS conv_thr = 1.00000e-06 electron_maxstep = 200 mixing_beta = 7.00000e-01 startingpot = "atomic" startingwfc = "atomic+random" / &IONS ion_dynamics = "bfgs" / ATOMIC_SPECIES Zn 65.39000 Zn.pbe-van.UPF S 32.06600 S.pbe-van_bm.UPF

A file called ‘submit.sh’ for CALYPSO:

#!/bin/sh source compilervars.sh intel64 mpirun -np 8 '/home/dmishra_du/QE/qe-6.1/bin/pw.x' -inp pw_input> out.pw